Q1.
(a) Copper is a metal.
Explain how it conducts electricity.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(b)
Graphite is a non-metal.
Use the information to explain why graphite conducts electricity.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 5 marks)
Q2.
(a)
The diagrams represent the atomic structures of two gases, hydrogen and helium.
Hydrogen gas is made up of diatomic molecules (molecules with two atoms).
Helium gas exists as single atoms.
Page 1 of 57
(i)
How is a molecule of hydrogen formed from two hydrogen atoms?
(You may use a diagram as part of your answer)
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(ii)
Why does helium exist only as single atoms?
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(b)
Hydrogen combines with carbon to form methane.
Each molecule contains four hydrogen atoms strongly bonded to a carbon atom.
Explain why methane has a low boiling point.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 6 marks)
Q3.
(a)
Write down the symbols for
lithium ................................................................................
fluorine ...............................................................................
(2)
Page 2 of 57
(b)
The electronic structure of a lithium atom can be shown like this:
In a similar way, complete this diagram to show the electronic structure of a fluorine atom.
(1)
(c)
A lithium atom can lose one electron to form a lithium ion which can be written (2)+
A fluorine atom can gain one electron to form a fluoride ion.
Choose from the list the correct way to write the fluoride ion.
(2,6)+
(2,7)+
(2,7)-
(2,8)+
(2,8)–
Answer ..........................................
(2)
(Total 5 marks)
Q4.
The diagrams show the giant structures of sodium chloride and diamond.
sodium chloride (melting point 801°C)
(a)
diamond (melting point 4800°C)
The equation shows how sodium choride could be formed.
Balance the equation.
Na
+
Cl2
→
Na Cl
(1)
Page 3 of 57
(b)
By reference to the detailed structure of sodium chloride explain fully why:
(i)
sodium chloride has a quite high melting point,
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(1)
(ii)
solid sodium chloride melts when it is heated strongly,
...........................................................................................................................
...........................................................................................................................
(2)
(iii)
molten sodium chloride will conduct electricity.
...........................................................................................................................
...........................................................................................................................
(1)
(c)
By reference to the detailed structure of diamond, explain why the melting point of
diamond, is higher than that of sodium chloride.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 7 marks)
Page 4 of 57
Q5.
(a) The diagrams below show the electronic structure of a magnesium atom and a
magnesium ion.
What is the charge on the magnesium ion? ...............................................................
(2)
(b)
Calcium bromide has the formula CaBr2.
What does this tell you about the ions in this compound?
....................................................................................................................................
....................................................................................................................................
(2)
(Total 4 marks)
Q6.
The diagram shows one molecule of the compound ammonia.
Write down everything that the diagram tells you about each molecule of ammonia.
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
...............................................................................................................................................
(Total 4 marks)
Page 5 of 57
##
Atoms of calcium, phosphorus and fluorine are represented below, each with its mass
number and proton number.
(a)
Use this information to complete the table.
CALCIUM
Number of protons in the nucleus
20
Number of neutrons in the nucleus
20
PHOSPHOROUS
Number of electrons
FLUORINE
9
16
15
9
(3)
(b)
Calcium and fluorine atoms can combine to form the compound calcium fluoride, CaF2.
The fluoride ion is represented by F–.
(i)
Explain how the fluorine atom forms a fluoride ion.
..........................................................................................................................
..........................................................................................................................
(2)
(ii)
How is the calcium ion represented?
..........................................................................................................................
(2)
(c)
Phosphorus and fluorine form a covalent compound, phosphorus trifluoride.
Complete the sentences below which are about this compound.
Phosphorus trifluoride is made up of phosphorus and fluorine ................................
These are joined together by sharing pairs of ............................................... to form
phosphorus trifluoride ........................................................ .
(3)
Page 6 of 57
(d)
(i)
Sodium chloride, an ionic compound, has a high melting point whereas paraffin
wax, a molecular compound, melts easily.
Explain why.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(2)
(ii)
Molten ionic compounds conduct electricity but molecular compounds are nonconductors, even when liquid.
Explain why.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(2)
(Total 14 marks)
Q8.
The diagram shows the elements in Group 4 of the periodic table.
Page 7 of 57
Carbon is a non-metal and silicon is usually considered to be a non-metal.
Tin and lead have all the usual properties of metals.
Germanium has these properties:
•
grey-white shiny solid
•
melting point 937°C
•
semi-conductor
•
reacts with chlorine to form the chloride (GeCl4) which is a liquid
molecular compound
•
(a)
germanium oxide reacts with acids to form a salt solution and water. It also reacts
with alkalis.
With reference to their structure, explain why tin and lead are good conductors
of electricity.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(b)
Would you classify germanium as a metal or as a non-metal? Give your reasons.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 6 marks)
Page 8 of 57
Q9.
(a)
(i)
Balance these chemical equations.
H2 +
O2 →
H 2O
(1)
(ii)
Al +
O2 →
Al 2O3
(1)
(b)
Briefly explain why an unbalanced chemical equation cannot fully describe a reaction.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(c)
Explain, as fully as you can, why a water molecule contains two hydrogen atoms but a
hydrogen chloride molecule contains only one.
(You may use a diagram in your answer if you wish).
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 7 marks)
Q10.
(a)
The formula for ammonia is NH3. What does the formula tell you about each molecule
of ammonia?
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
Page 9 of 57
(b)
Ammonia is used to make nitric acid (HNO3). Calculate the formula mass (Mr) for nitric
acid. (Show your working).
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
(Total 6 marks)
Q11.
The questions which follow refer to the element hydrogen.
(a)
Draw a diagram to show the bonding in one molecule of hydrogen.
(2)
Page 10 of 57
(b)
The table gives information about two compounds which contain hydrogen.
Use the information in the table to explain why it is difficult to classify hydrogen as a metal
or a non metal.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(4)
(Total 6 marks)
Q12.
Sodium carbonate reacts with acids.
(i)
Complete the word equation.
sodium carbonate + hydrochloric acid → sodium chloride + ...................... + water
(1)
(ii)
Name the salt produced if sodium carbonate reacts with dilute nitric acid.
...........................................................................................................................
(1)
(Total 2 marks)
Page 11 of 57
Q13.
(a) The chart shows the reactions of the metal calcium with water, oxygen and dilute
hydrochloric acid.
Name (i)
solution A .................................................................................................
(ii)
solid B .....................................................................................................
(iii)
gas C ........................................................................................................
(3)
(b)
The diagrams below show the electronic structure of an atom of calcium and an atom
of oxygen.
Describe fully what happens to its electrons when:
(i)
a calcium atom forms a calcium ion. State the charge on the calcium ion formed.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(3)
(ii)
an oxygen atom forms an oxygen ion. State the charge on the oxygen ion formed.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(3)
Page 12 of 57
(c)
Calcium oxide is an ionic compound. Why do ionic compounds have high melting points?
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 11 marks)
Q14.
(a) By reference to their structure, explain how the particles in a piece of metal are held
together and how the shape of the metal can be changed without it breaking.
(You may use a diagram in your answer.)
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(5)
Page 13 of 57
(b)
Explain why metals are good conductors of electricity and suggest why this conductivity
increases across the periodic table from sodium to magnesium to aluminium.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(4)
(Total 9 marks)
Q15.
Chlorine will combine with the non-metal element, carbon, to form this molecular
compound.
(a)
What is the type of bond in this molecule?
.....................................................................................................................................
(1)
(b)
Explain how these bonds are formed. (You may use a diagram).
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 3 marks)
Page 14 of 57
Q16.
Magnesium oxide is a compound, made up of magnesium ions and oxide ions.
(a)
What is the charge on each magnesium ion? .............................................................
(1)
(b)
Explain how the magnesium ions get this charge.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 3 marks)
Q17.
Part of a reactivity series is:
(a)
Carbon is used in blast furnaces to obtain iron and zinc from their oxides, but electrolysis
has to be used to obtain aluminium from its oxide.
Draw an arrow on the reactivity series above to show where carbon fits into the series.
(1)
(b)
Predict the method of extraction used to obtain calcium from its ore and explain your
answer.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
Page 15 of 57
(c)
The formula for zinc oxide is ZnO. Write a balanced equation for the extraction of zinc in
the blast furnace.
.....................................................................................................................................
(2)
(Total 5 marks)
Q18.
(a)
The equation for the reaction that takes place when ammonium chloride is heated is:
NH4Cl(s)
ammonium chloride
NH3(g)
ammonia
+
HCl (g)
hydrogen chloride
The diagram shows how a teacher demonstrated this reaction. The demonstration was
carried out in a fume cupboard.
(i)
Apart from the gases normally in the atmosphere, which two gases would be
at X?
..................................................... and ...........................................................
(1)
(ii)
Name the white solid that has formed at Y.
..........................................................................................................................
(1)
(iii)
Why was the demonstration carried out in a fume cupboard?
..........................................................................................................................
..........................................................................................................................
(1)
Page 16 of 57
(iv)
Complete the four spaces in the passage.
The chemical formula of ammonia is NH3. This shows that there is one atom of
.......................................... and three atoms of .................................. in each
......................................... of ammonia. These atoms are joined by bonds that
are formed by sharing pairs of electrons. This type of bond is called
a ............................... bond.
(4)
(b)
Electrons, neutrons and protons are sub-atomic particles.
(i)
Complete the three spaces in the table.
Name of sub-atomic
particle
Relative mass
Relative charge
...............................
1
+1
...............................
1
0
...............................
–1
(2)
(ii)
Which two sub-atomic particles are in the nucleus of an atom?
........................................................... and ...............................................
(1)
(Total 10 marks)
Q19.
(a)
The diagram shows part of the ionic lattice of a sodium chloride crystal.
Page 17 of 57
(i)
Complete the spaces in the table to give information about both of the ions in this
lattice.
Name of ion
Charge
.....................................................
.....................................................
.....................................................
.....................................................
(2)
(ii)
When it is solid, sodium chloride will not conduct electricity. However, molten sodium
chloride will conduct electricity. Explain this difference.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(2)
(iii)
Complete the sentence.
Sodium chloride conducts electricity when it is molten and when it is
..........................................................................................................................
(1)
(b)
The symbol for a calcium atom can be shown like this:
(i)
What is the mass number of this atom?
..........................................................................................................................
(1)
(ii)
What information is given by the mass number?
..........................................................................................................................
..........................................................................................................................
(1)
(c)
Calcium burns in oxygen with a brick-red flame. The product is a white solid. It is calcium
oxide and its formula is CaO.
(i)
Balance the chemical equation for the reaction.
Ca(s) + O2(g) → CaO(s)
(1)
Page 18 of 57
(ii)
Describe, in terms of electrons, what happens to a calcium atom when it becomes a
calcium ion.
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
..........................................................................................................................
(2)
(Total 10 marks)
Q20.
Part of the Periodic Table showing the symbols for the first twenty elements is given below.
(a)
Draw diagrams showing the arrangement of electrons (electronic structures) in:
(i)
an aluminium atom;
(ii)
a chlorine atom.
(2)
(b)
(i)
Use electronic structures to help you show why the formula of sodium oxide is Na2O.
(3)
Page 19 of 57
(ii)
State why the formation of sodium ions is classified as an oxidation.
..........................................................................................................................
..........................................................................................................................
(1)
(Total 6 marks)
Q21.
Ammonium nitrate and ammonium sulphate are used as fertilisers.
(i)
Which acid reacts with ammonia to form ammonium nitrate?
....................................................................................................................................
(1)
(ii)
Which acid reacts with ammonia to form ammonium sulphate?
....................................................................................................................................
(1)
(iii)
The reactions in (i) and (ii) are both exothermic. How can you tell that a reaction is
exothermic?
....................................................................................................................................
....................................................................................................................................
(1)
Page 20 of 57
(iv)
The reactions in (i) and (ii) are both examples of acid + base reactions. What is the name
of the chemical change which takes place in every acid + base reaction?
....................................................................................................................................
(1)
(Total 4 marks)
Q22.
The drawing shows a container of a compound called magnesium chloride.
(i)
How many elements are joined together to form magnesium chloride?
....................................................................................................................................
(1)
(ii)
Magnesium chloride is an ionic compound. What are the names of its ions?
................................................. ions and ................................................. ions
(1)
(iii)
How many negative ions are there in the formula for magnesium chloride?
....................................................................................................................................
(1)
(iv)
Complete the sentence.
Ions are atoms, or groups of atoms, which have lost or gained
......................................... .
(1)
Page 21 of 57
(v)
Suggest three properties which magnesium chloride has because it is an ionic
compound.
Property 1 ...................................................................................................................
....................................................................................................................................
Property 2 ..................................................................................................................
....................................................................................................................................
Property 3 ..................................................................................................................
....................................................................................................................................
(3)
(Total 7 marks)
Q23.
(a)
Atoms are made of sub-atomic particles. Complete the six spaces in the table.
Name of sub-atomic
particle
Relative mass
.................................
Relative charge
......................
Neutron
.....................
.......................
.................................
1
.......................
(3)
(b)
Complete the spaces in the sentences.
(i)
The atomic number of an atom is the number of ..................................... in its
nucleus and is equal to the number of ..................................................... if the
atom is not charged.
(1)
(ii)
The mass number of an atom is the total number of ................................. and
...................................... in its nucleus.
(1)
Page 22 of 57
(c)
The table gives information about the atoms of three elements.
Number of electrons in:
Name of
element
Chemical
symbol
Fluorine
1st
shell
2nd
shell
3rd
shell
F
2
7
0
Neon
Ne
2
8
0
Sodium
Na
2
8
1
Two of these elements can react together to form a chemical compound.
(i)
What is the name and the formula of this compound?
Name ................................................... Formula ..........................................
(2)
(ii)
What type of bonding holds this compound together?
...........................................................................................................................
(1)
(iii)
Explain, in terms of electron transfer, how the bonding occurs in this compound.
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
...........................................................................................................................
(2)
(Total 10 marks)
##
In this question you will need to use the following information:
Relative atomic masses: H 1; O 16; Mg 24.
The volume of one mole of any gas is 24 dm3 at room
temperature and atmospheric pressure.
Page 23 of 57
The diagram shows a chemical reaction taking place in a conical flask.
The balanced equation for this reaction is:
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
(a)
Write a balanced ionic equation for this reaction.
....................................................................................................................................
(2)
(b)
Calculate the mass of magnesium required to produce 0.50 g of hydrogen. Show clearly
how you work out your final answer and give the unit.
.....................................................................................................................................
.....................................................................................................................................
Mass = ...............................
(2)
(c)
(i)
Draw a diagram to show how the electrons are arranged in a hydrogen molecule.
(1)
(ii)
What is the name of the type of chemical bond between the hydrogen atoms in a
hydrogen molecule?
...........................................................................................................................
(1)
Page 24 of 57
(d)
The chemical formula for hydrogen peroxide is H2O2.
Calculate, to the nearest whole number, the percentage, by mass, of hydrogen in
hydrogen peroxide. Show clearly how you work out your answer.
....................................................................................................................................
....................................................................................................................................
Percentage = ................................. %
(2)
(Total 8 marks)
Q25.
Electrons, neutrons and protons are sub-atomic particles.
(a)
Complete the six spaces in the following table.
Name of sub-atomic
particle
Relative mass
Relative charge
.......................................
1
........................................
.......................................
........................................
0
.......................................
.........................................
(3)
(b)
An aluminium atom has 13 electrons. How are these arranged in shells around the
nucleus?
....................................................................................................................................
(1)
(c)
Chromium atoms have 24 protons and 28 neutrons.
(i)
How many electrons does each neutral chromium atom have?
...........................................................................................................................
(1)
(ii)
What is the mass number of chromium?
...........................................................................................................................
(1)
(d)
What change occurs to an atom which undergoes the process of reduction in a chemical
reaction?
....................................................................................................................................
....................................................................................................................................
(1)
Page 25 of 57
(e)
The diagram shows part of the ionic lattice of a sodium chloride crystal.
Explain why the ions in this lattice stay in place.
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
....................................................................................................................................
(3)
(Total 10 marks)
Q26.
(a) Every chemical element has a chemical symbol. Choose the correct chemical
symbols from the box and complete the three spaces in the table.
C
Co
Cu
Fe
I
Ir
Zn
Name of element
Chemical symbol
Copper
....................................
Iron
....................................
Zinc
....................................
Zr
(3)
Page 26 of 57
(b)
Give one use for each of the following metals. You should give a different use for each
metal.
Copper ......................................................................................................................
....................................................................................................................................
Iron ...........................................................................................................................
....................................................................................................................................
Zinc ...........................................................................................................................
....................................................................................................................................
(3)
(c)
Give four physical properties which metals usually have.
1. ................................................................................................................................
....................................................................................................................................
2. ................................................................................................................................
....................................................................................................................................
3. ................................................................................................................................
....................................................................................................................................
4. ................................................................................................................................
....................................................................................................................................
(4)
(d)
Metals usually form ionic compounds. Give one property of an ionic compound.
....................................................................................................................................
....................................................................................................................................
(1)
Page 27 of 57
(e)
The diagrams show two different atoms, atom A and atom B.
Atom A
(i)
Atom B
Complete the following sentence.
For these two atoms to become ions one ............................................ would
be transferred from atom ........... to atom ........... .
(1)
(ii)
Atom A and atom B are from different elements. How can you tell this from their
nuclei?
...........................................................................................................................
...........................................................................................................................
(1)
(Total 13 marks)
Q27.
(i)
Complete the drawing to show the electron structure of a hydrogen fluoride molecule.
Draw electrons as dots or crosses.
(1)
Page 28 of 57
(ii)
Explain why hydrogen fluoride is a gas at room temperature.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(2)
(Total 3 marks)
Q28.
(a) A piece of lithium is placed on the surface of some water in a beaker.
Hydrogen is given off.
Lithium hydroxide is also formed.
Write a word equation for this reaction.
.....................................................................................................................................
(2)
(b)
The diagram shows the structure of a molecule of methane.
Write down everything that this diagram tells you about a methane molecule.
To gain full marks in this question you should write your ideas in good English. Put them
into a sensible order and use the correct scientific words.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(4)
(Total 6 marks)
Page 29 of 57
Q29.
The diagram shows the structure of diamond.
(a)
To gain full marks for this question you should write your ideas in good English. Put them
into a sensible order and use the correct scientific words.
Explain, as fully as you can, why diamond has a high melting point.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
Page 30 of 57
(b)
The diagram below shows the outer electron shells of five carbon atoms in the giant lattice
of diamond.
Carbon atom C forms bonds with each of the carbon atoms W, X, Y and Z.
Draw the positions of all the electrons in the outer shells of each of carbon atoms C, W, X,
Y and Z.
(3)
(Total 6 marks)
Page 31 of 57
Q30.
The diagram shows the structure of diamond.
(a)
To gain full marks for this question you should write your ideas in good English. Put them
into a sensible order and use the correct scientific words.
Explain, as fully as you can, why diamond has a high melting point.
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
.....................................................................................................................................
(3)
Page 32 of 57
(b)
The diagram below shows the outer electron shells of five carbon atoms in the giant lattice
of diamond.
Carbon atom C forms bonds with each of the carbon atoms W, X, Y and Z.
Draw the positions of all the electrons in the outer shells of each of carbon atoms C, W, X,
Y and Z.
(3)
(Total 6 marks)
Page 33 of 57
M1.
(a)
•
idea that
copper has free electrons / electrons that move
throughout the structure
gains 1 mark
but
•
in copper, electrons from the highest (occupied) energy
level /outer shell, are
free / can move throughout the structure
gains 2 marks
2
(b)
idea that
•
in graphite, only three bonds are formed by each carbon atom
for 1 mark
•
one outer electron (per atom), free to move
for 1 mark
•
an electric current is a flow of (free) electrons*
for 1 mark
(* this mark to be given in either (a) or (b) but not in both)
3
[5]
M2.
(a)
(i)
idea that
•
two hydrogen atoms share one pair of electrons
•
linked by a covalent bond
•
each then has two outer electrons / a full outer shell / two
•
electrons in the highest (occupied) energy level
(2 marks may be awarded for a correct electron diagram i.e. with electrons on
boundary of or within marked area).
any two for 1 mark each
2
Page 34 of 57
(ii)
idea that
•
helium atoms do not give / take / share electrons / react
•
because the (outer) shell / orbit is full
or
•
highest (occupied) energy level is full
(but not just “contains two electrons”)
for 1 mark each
2
(b)
idea that
•
the (attractive) forces between molecules are weak
(not bonds between atoms)
•
so little energy is required / it is easy for molecules to escape from the liquid*
/ escape from other molecules*
(allow evaporate / change into a gas)
for 1 mark each
2
[6]
M3.
(a)
lithium = Li
(ignore mass / atomic numbers)
fluorine = F (do not allow if case is incorrect)
for 1 mark each
2
(b)
(allow ● or o for electrons)
(allow any positions for the seven electrons added provided
they are on the outer ring)
for 1 mark
1
(c)
(2,8)+ or (2,7)–
(brackets not required) gains 1 mark
but (2,8)–
gains 2 marks
2
[5]
Page 35 of 57
M4.
(a)
2 Na + Cl2 → 2 NaCl allow 2 Na+ Cl– for 1 mark
(allow Na + ½Cl2 → Na Cl)
1
(b)
(i)
idea that
•
it has strong (attractive) forces/bonds between ions / charged
particles
for 1 mark
(not ‘..it has a rigid structure’- this defines a solid or ‘...particles
close together’ – they are in a liquid)
1
(ii)
ideas that
•
there is increased vibration of ions / particles on heating
•
ions have sufficient energy to overcome attractive forces / to
break out of the
•
rigid structure / to move about
(must be in terms of increased energy of particles lions)
each for 1 mark
2
(iii)
•
ions can go to electrodes / ions are free to move
for 1 mark
[do not credit ‘ions carry charges’]
1
(c)
ideas that
•
it has stronger attractive forces between atoms/particles (not ‘ions’)
•
each carbon atom forms covalent bonds with neighbouring atoms
each for 1 mark
2
[7]
Page 36 of 57
M5.
(a)
positive / + / 2
gains 1 mark
but 2+ / ++ / +2
gains 2 marks
2
(b)
Ideas that: 2
Ca2+
Br- [Do not disqualify for "bromine" ions]
Ions / They are in the ratio 1:2
any two for 1 mark each
2
[4]
M6.
idea that
•
contains nitrogen atoms
•
contains hydrogen atoms
•
atoms are chemically bonded
•
ratio of one nitrogen to three hydrogen (atoms) formula of ammonia is NH3
NOT linked/joined
for 1 mark each
[4]
M7.
(a)
Calcium
No of protons
Fluorine
15
No of neutrons
No of electrons
Phosphorus
10
20
for 1 mark each
3
(b)
(i)
gain of electron(s)
from (atoms) (of) calcium
for 1 mark
2
Page 37 of 57
(ii)
Ca+
gains 1 mark
but superscript only Ca2+ / Ca ++
gains 2 marks
2
(c)
atoms
electrons
molecule(s)
not compound
each for 1 mark
3
(d)
(i)
ideas that
•
ionic – strong forces between ions
•
molecular – weak forces between molecules
each for 1 mark
2
(ii)
ideas that
•
ionic – ions/charged particles are free to move
•
molecular -molecules do not carry a charge
each for 1 mark
2
[14]
##
(a)
idea that
some of the outer electrons of the atoms are free to move
can move anywhere across the (giant) structure
the flow of electricity is a stream of electrons
each for 1 mark
or electrons carry a (negative electrical) charge
3
Page 38 of 57
(b)
metal element
[shiny] appearance
[high] melting point
forms an oxide that reacts with acids to make a salt
1 of these for 1 mark
non metal element
forms an oxide that reacts with alkalis
with chlorine forms a molecular chloride
1 of these for 1 mark
semi-conductor suggests in between
this, or any other for 1further mark
[NB Maximum of 2 for arguing metal/non-metal only]
Under each head
1 wrong reason → maximum of 1 available
2 wrong reasons → no mark available]
3
[6]
M9.
(a)
(i)
2 H2 + O2 → 2 H2O (allow H2 + ½O2 → H2O)
both circled for 1 mark
1
(ii)
4 A1 + 3 O2 → 2 A12O3
all circled for 1 mark
1
(b)
idea that:
must end up with the same number of atoms
otherwise matter is shown to be lost/gained
doesn’t show correct amount of each element/compared
each for 1 mark
2
(c)
idea that:
oxygen has 2 electrons short in outer shell ) in words or
chlorine has 1 electron short in outer shell ) indicated on diagram
(shared pair/covalent bond with) hydrogen
atom supplies one further electron*
*(but do not allow hydrogen gives away electron or ionic bond)
for 1 mark each
3
[7]
Page 39 of 57
M10.
(a) reference to
hydrogen (atoms)
)
nitrogen (atoms)
)
each for 1 mark
but not molecules
ratio of 1N to 3H atoms
for 1 further mark
or 1 nitrogen atom and 3 hydrogen atoms
(ignore any incorrect statements about nature of bonding)
3
(b)
evidence of
H=1
N = 14
O = 16
gains 1 mark
but
H=1
N = 14
O = 16 × 3 or 48
gains 2 marks
but 63
gains 3 marks
3
[6]
M11.
(a)
correct representation of 1 atom of hydrogen e.g.
gains 1 mark
but correct representation of 1 molecule of hydrogen e.g. or H-H
gains 2 marks
2
Page 40 of 57
(b)
idea that:
hydrogen/metals form positive ions/lose electrons
gains 1 mark
but hydrogen and the metals form positive ions/lose electrons
gains 2 marks
hydrogen/non-metals form covalent bonds/share electrons
gains 1 mark
but hydrogen and the non-metals form covalent bonds/share electrons
gains 2 marks
4
[6]
M12.
(i)
carbon dioxide (allow CO2)
for 1 mark
1
(ii)
sodium nitrate (accept correct formula)
for 1 mark
1
[2]
M13.
(a)
(i)
A calcium hydroxide/limewater/Ca(OH)2 not CaOH
(ii)
B calcium oxide/Quicklime/CaO
(iii)
C hydrogen/H2 (accept correct formulae)/ not H2/H
each for 1 mark
3
(b)
(i)
idea that
electrons are lost (by the calcium atom)
gains1 mark
but two electrons are lost (by the calcium atom)/lose outer electrons to get full shell
gains 2 marks
calcium ions are 2+
for 1 mark
Page 41 of 57
(ii)
electrons are gained (by the oxygen atom)
gains 1 mark
but two electrons are gained (by the oxygen atom)/gain electrons to get full outer
shell
gains 2 marks
oxygen ions are 2–
for 1 mark
6
(b)
(c)
(i)(ii) needs:
electron loss/gain
number (2)
charge (+/–)
idea that
they are held together by many/strong forces/bonds
a lot of energy/high temperature is required to break these forces/bonds
each for 1 mark
2
[11]
##
(a)
Idea that
the electrons do not belong to specific atoms/delocalised electrons
[credit if done on appropriate diagram]
metal atoms form positive ions
the attraction which exists between particles with opposite charges, holds the metal together
no specific bonds exist between adjacent atoms/ions
atoms/ions can slide over each other so allowing metals to bend
each for 1 mark
5
(b)
some electrons in the structure are delocalised/free to move
for 1 mark
these free electrons carry the electric current
for 1 mark
from left to right across the period, atoms of elements have
more free electrons
gains 1 mark
but from left to right across the period, atoms of elements have more free
electrons because they have more electrons in the outer shells
gains 2 marks
4
[9]
Page 42 of 57
##
(a)
covalent bonds
for 1 mark
1
(b)
any reference to shared electrons
gains 1 mark
but idea that bond is shared pair of electrons
gains 2 marks
2
[3]
##
(a)
positive
for 1 mark
1
(b)
any reference to loss of electrons
for 1 mark
reference to charge being +2 (in (a)) or to loss of 2 electrons (in (b))
for 1 mark
2
[3]
M17.
(a)
This part was not marked
1
(b)
electrolysis
1
because calcium is more reactive (than aluminium or carbon)
accept it is more reactive
or very reactive
1
OR
in a blast furnace
1
because calcium is less reactive (than carbon or lower)
1
Page 43 of 57
(c)
any equation from
1 mark for correct formulae
1 mark for balancing
2ZnO + C → 2Zn + CO2
ZnO + CO → Zn + CO2
ZnO + C → Zn + CO
1
[5]
M18.
(a)
(i)
ammonia and hydrogen chloride
both required either order
accept formulae if correct in every detail
1
(ii)
ammonium chloride / NH4Cl
do not credit ammonia chloride
1
(iii)
the fumes / gases / are poisonous / toxic
or ammonia and hydrogen chloride are
poisonous / toxic / lethal
accept just ammonia is poisonous / toxic
accept just hydrogen chloride is
poisonous / toxic
accept vapour is poisonous / toxic
do not credit just fumes are dangerous
or harmful
1
(iv)
nitrogen
do not credit N/N2
1
hydrogen
do not credit H/H2
1
molecule
do not credit compound or mole
1
covalent
accept single / molecular
1
Page 44 of 57
(b)
(i)
proton
neutron
electron
either all three correct
or one or two correct
however do not credit a response
which is repeated
2
(ii)
protons and neutrons
both required in either order
1
[10]
M19.
(a)
(i)
sodium........ positive or +
both required
1
chloride... negative or –
both required
do not credit chlorine
1
(ii)
ions not free (to move) in solid crystal / lattice
ions are free to move when sodium chloride is molten
1
or ions are mobile
do not credit when ions are molten
allow 'particles' for ions (1) mark
do not credit electrons etc
1
(iii)
dissolved in water
or in aqueous solution
accept in solution
accept in water
or when a gas/ vapour or solid it will not
1
(b)
(i)
40
1
(ii)
(total) number of protons and neutrons (in the nucleus)
1
(c)
(i)
2Ca + O2 -+ 2CaO
accept any 2n : n : 2n ratio
do not credit if any other change has been made
1
Page 45 of 57
(ii)
any two from
electron(s) is / are lost
from the outer shell / orbit / ring
or from the shell furthest the nucleus
or from the 4th shell
two / both (electrons are lost)
accept two electrons are lost for (2)marks
accept both electrons are lost from the
atom for (1) mark
2
[10]
M20.
(a)
(i)
rings of 2, 8 and 3 electrons
credit 2, 8, 3 pay particular attention to the outer shell in diagrams
1
(ii)
rings of 2, 8 and 7 electrons
credit 2, 8, 7 pay particular attention to the outer shell in diagrams
1
(b)
(i)
labels not required on atoms
charges need to be shown on ions
reference to outer shell is required otherwise a maximum of two
marks
structure of atoms/ions marks
(ring of 2, 8, 1 for sodium) or the outer shell of sodium only contains 1 electron
credit 2, 8, 1 or an ion 2, 8 or two circles and 1 electron in outer
shell
1
(ring of 2, 6 for oxygen) or outer shell only contains 6 electrons
credit 2, 6 or an ion 2, 8 or two circles
1
transfer of electrons mark
two sodiums needed to supply two outer electrons to oxygen to complete
the (one oxygen's) outer shell
award maximum of two marks if a covalent structure is given
credit two rings of electrons for sodium showing outer electrons
transferring to outer shell of one oxygen for three marks
do not accept diagrams showing overlapping rings for third mark
1
Page 46 of 57
(ii)
loses an electron
credit atoms lose electrons or oxygen takes the electron ignore oil
rig
1
[6]
M21.
NOTE
In this question and throughout the Paper, if the name of a chemical is
asked for, then the formula is acceptable only if it is correct in every detail.
If the name is correct and the candidate has tried to be ‘helpful’ by giving,
in addition, an incorrect version of the formula, then this is acceptable
provided it does not lead to ambiguity.
(i)
nitric (acid)
accept HN03
1
(ii)
sulphuric (acid)
accept H2SO4
1
(iii)
heat given out
or temperature rise
or energy given out
or steam
do not credit just ‘use a thermometer’
do not credit just 'change in temperature'
1
(iv)
neutralisation
accept neutralise
accept neutral
accept formation of salt or water
do not credit exothermic
1
[4]
Page 47 of 57
M22.
(i)
two
or 2
1
(ii)
magnesium and chloride
either order
not positive / negative
do not credit’chlorine’
accept Mg++ and Cldo not credit just Mg and Cl–
accept cation(s) and anion(s)
1
(iii)
2
1
(iv)
electrons
accept charges
1
(v)
any three from
•
(is a) giant structure/lattice structure
•
crystalline / hard
accept just 'crystals(s)’
•
high melting point / solid
•
high boiling point
•
conductor (of electricity) when dissolved in water
or conductor (of electricity) when ions are free to move
•
conductor (of electricity) when molten
•
soluble in water
3
[7]
M23.
(a)
both correct in each row
electron ...– (1)
allow negative
1
1 .......... 0
allow neutral or none
1
proton .....+ (1)
allow positive
1
Page 48 of 57
(b)
(i)
protons...electrons
both correct in correct order
1
(ii)
protons....neutrons
both correct in either order
1
(c)
(i)
sodium fluoride
do not credit sodium fluorine
1
NaF
must be correct in every detail
do not credit NAF and the like
1
(ii)
ionic
accept ion (bonding)
do not credit ironic or iron (bonding)
1
(iii)
electron transferred from sodium to fluorine
accept electron transferred from metal to non-metal
either positive sodium ion and negative fluoride ion
or correctly identified by the symbols Na+ and F- accept ‘positive
sodium ion and negative fluorine ion’
1
or attracted because have opposite charge(s)
or (atoms/ions) form an (ionic) lattice or (atoms/ions) form a
crystal
e.g.
or both marks may be gained by a suitable dot and cross diagram
1
[10]
M24.
(a)
Mg + 2H+ → Mg2+ + H2
* reactants correct in every detail
* products correct in every detail
if the spectator ions are sown then (1) mark should be credited but
only if they are shown correctly on both sides
e.g.
Mg + 2H+ + 2CI- → Mg2+ + 2CI- + H2
2
Page 49 of 57
(b)
24 (parts) of magnesium → 2 (parts)
1
of hydrogen or equally clear working (so) 6 grams/g (are needed)
1
unit required
(c)
(i)
two (and no more) atoms shown to be sharing their single electrons
examples
do not credit if anything which contradicts the impression that these
are hydrogen atoms
1
(ii)
(single) covalent (bond)
1
(d)
(×100) = 6 (just 6 is worth (1) mark)
1
× 100 = 6 or similar is (0)
do not credit 5.8823529 and the like
1
[8]
M25.
(a)
proton + (1)
both required
neutron 1
both required
electron – (1)
both required
3
(b)
2.8.3
accept words or diagram to this effect
1
(c)
(i)
24
1
(ii)
52
1
Page 50 of 57
(d)
any one of
•
gains one or more electrons
accept gains an electron
•
becomes an anion
do not credit becomes an ion
•
becomes a negative ion
1
(e)
sodium ions have a (single) positive
charge and chloride ions have a
(single) negative charge
do not credit ‘chlorine ions’ but
allow this error to be carried forward
1
ions with opposite charge are
attracted (to each other)
or the positive ions and the negative ions are attracted (to each
other)
or the sodium ions and the chloride ions are attracted (to each
other)
1
(positive and negative) ions are
arranged alternatively (in each
direction or dimension)
or ions with the same charge are repelled (by each other) no mark
for just ionic bonds
1
[10]
M26.
(a)
Cu
1
Fe
1
Zn
1
(b)
one significant use for each metal
do not credit vague answers such as ‘in experiments’ and the like
do not credit the same use more than once
copper
examples:
do not credit diet supplement
1
Page 51 of 57
•
coins or coinage (metal) or make alloys or bronze or brass
•
conducting electricity or (electrical) wiring or motors or cables
•
(domestic) (water) pipes
•
heat exchangers
•
roofing
•
steam pipes
•
stills or cooking utensils
accept any specified still e.g. whisky still
•
bracelets or rings
iron or steel answers
examples:
do not credit diet supplement
* access-hole covers (sometimes known as ‘manhole’ covers)
* catalyst (in the production of ammonia)
* manufacture of steel(s) or in the basic oxygen process
* named vehicle or transport or machinery or railings
any other uses for iron and steel can be credited provided that the
use is clear so, for example, ‘bridges’ and ‘railway lines’ would be
creditworthy but do not credit ‘buildings’ and ‘transport’ which are
too vague
1
zinc
examples:
do not credit diet supplement
* brass manufacture
* die castings
* rust prevention
* to galvanise (iron or steel) or (as a) protective coating
* battery casing
1
(c)
any four general properties of
do not credit hard or strong or tough or magnetic
•
are not brittle
accept can be bent (into shape) or flexible
•
can be hammered (into shape)
accept are malleable
•
can be stretched (into shape)
accept are ductile
Page 52 of 57
•
(good) conductors of heat
accept just ‘(good) conductor’ once only
•
(good) conductors of electricity
•
high boiling points
•
high density or heavy or dense
•
high melting points
•
ringing sound when struck
accept sonorous
•
solids (at room temperature)
accept shiny (when polished) or silvery
4
(d)
any one of
do not credit electron references
* (good) conductor (of electricity) when molten or liquid
accept dissolves in water or crystalline
* (good) conductor (of electricity) when in aqueous solution
accept (good) conductor (of electricity) when dissolved in water
* high melting point or high boiling point
do not credit just ‘solid’
1
(e)
(i)
electron from A to B
both parts required
1
(ii)
different numbers of protons
accept different atomic numbers do not credit references to
neutrons
1
[13]
M27.
(i)
1
Page 53 of 57
(ii)
weak forces
accept weak bonds
1
between molecules / intermolecular
reject intramolecular
1
[3]
M28.
(a)
LHS lithium + water
accept Li and H2O
accept hydrogen oxide for water
1
RHS hydrogen + lithium hydroxide
accept H2 and LiOH
ignore attempts at balancing
ignore charges
1
(b)
Quality of written communication
One mark for the correct use of any
three of the terms atom, covalent,
bond(ing), saturated, hydrocarbon
or alkane
1
any three from:
one / the carbon (atom)
reject molecules once
four hydrogen (atoms)
shape / properties neutral
CH4
hydrocarbon
saturated / single bond
covalent bond / shared electrons
alkane
reject ionic bond
3
[6]
Page 54 of 57
M29.
(a) Quality of written communication: All scientific words used correctly
(covalent, bonds, atoms)
1
any two from
•
large numbers of covalent bonds
allow giant lattice / structure
•
between atoms
do not accept between molecules
•
(covalent) bonds strong
accept need much energy to break
2
(b)
each carbon has 4 electrons
1
one shared pair
1
four shared pairs
1
[6]
Page 55 of 57
M30.
(a) Quality of written communication: All scientific words used correctly
(covalent, bonds, atoms)
1
any two from
•
large numbers of covalent bonds
allow giant lattice / structure
•
between atoms
do not accept between molecules
•
(covalent) bonds strong
accept need much energy to break
2
(b)
each carbon has 4 electrons
1
one shared pair
1
four shared pairs
1
[6]
Page 56 of 57
Page 57 of 57