National Chemistry Topic 3
Bonding, Structure & Properties of Substances
Homework 1
1.
Most atoms do not exist as single atoms but prefer to be bonded to each
other. Explain the reason for this.
2.
Electrons that orbit the nucleus are arranged in energy levels. Each
energy level can only hold a maximum number of electrons.
1
a) Use your data book to find the electron arrangement for:
i)
ii)
iii)
iv)
a fluorine atom
a magnesium atom
a calcium atom
an argon atom
2
b) Copy and complete the table below:
Energy level
1
2
3
3.
Maximum number of electrons
1
Draw target diagrams to show the arrangement of electrons in atoms of:
a)
b)
c)
d)
lithium
aluminium
chlorine
argon
4
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National Chemistry Topic 3
Bonding, Structure & Properties of Substances
Homework 2
1.
The atoms in a hydrogen molecule are held together by a covalent bond.
Explain what is meant by:
a) a molecule
b) a covalent bond
c) Draw a diagram to show how two hydrogen atoms combine to form a
molecule of hydrogen.
2.
1
1
1
There are 7 elements in the periodic table that exist as diatomic
elements.
a)
Copy and complete the paragraph below by choosing one bold answer to
fill the blank.
A diatomic molecule is a molecule containing two metal/non-metal atoms
joined together by covalent bonds. A diatomic element is when a diatomic
molecule is formed from two identical/non-identical atoms.
2
b)
Name the seven diatomic elements.
1
c)
Make a list of all the diatomic molecules contained in the box below:
HCl
CH4
CO
H2O
NH3
2
NO2
Br2
N2
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National Chemistry Topic 3
Bonding, Structure & Properties of Substances
Homework 3
1.
Fluorine has the molecular formula F2 since it is an example of a diatomic
element. The structure of a fluorine molecule can be represented as F-F.
The – represents a covalent bond.
a)
Copy and complete the table for the molecules listed:
Diatomic element
Molecular formula
Structure of molecule
fluorine
F2
F-F
bromine
chlorine
oxygen
Cl-Cl
O2
3
nitrogen
b)
c)
2.
Which molecule has a double covalent bond?
Which molecule has a triple covalent bond?
By means of diagrams showing only outer electrons, show how covalent
1
1
bonds form in the following diatomic molecules:
a) chlorine
b) oxygen
c) nitrogen
3
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National Chemistry Topic 3
Bonding, Structure & Properties of Substances
Homework 4
1.
Which of the following compounds are made up of molecules?
a) sodium chloride
c) carbon sulphide
e) nitrogen oxide
2.
b) hydrogen chloride
d) aluminium nitrate
f) phosphorus oxide
Draw diagrams to show how the outer electrons are shared to form the
covalent bonds in molecules of:
a) hydrogen iodide HI
b) nitrogen trichloride NCl3
c) tetrachloromethane CCl4
3.
2
1
1
1
Make a drawing to show the shape of each of the following molecules:
1
i)
ii)
iii)
iv)
1
water
hydrogen fluoride
ammonia
methane
b)
Name the molecule , from the list above, which is
i) linear
ii) pyramidal
c)
What name is given to the shape of a methane molecule?
1
1
2
1
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National Chemistry Topic 3
Bonding, Structure & Properties of Substances
Homework 5
1a)
Use your data booklet to complete the table:
Compound
Melting point (ºC)
Boiling point (ºC)
Carbon dioxide
Silicon dioxide
b)
Explain why, although both of these compounds contain covalent bonds,
carbon dioxide is a gas at room temperature, whereas silicon dioxide is a
solid.
2.
2
2
Consider the structure of diamond which is made up of carbon atoms.
a) How many bonds does each carbon have inside the diamond structure?
b) Name the type of bonding present in diamond.
c) Elements in the same group tend to have similar chemical properties.
Select another non-metal from your periodic table which you think
would also have a similar structure to diamond.
1
1
1
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National Chemistry Topic 3
Bonding, Structure & Properties of Substances
Homework 6
1a)
b)
Name the type of bond that forms between a metal and a non-metal
atom.
Describe what happens to the outer shell electrons when this type of
bond forms.
2.
A compound is formed from a group 1 element and a group 7 element.
Choose 2 elements and show by means of a diagram what happens to the
outer electrons of the atoms involved.
3.
Hydrogen chloride is made up of molecules but sodium chloride exists as a
1
1
2
crystal lattice.
a) Explain what is meant by a lattice
b) Explain why ionic compounds have such high melting and boiling points
1
2
4.
A
CH4
D
B
H2S
E
O2
C
KNO3
F
CaCl2
NH3
Which box (or boxes) in the grid show the chemical formula of a
substance which is an ionic compound?
1
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National Chemistry Topic 3
Bonding, Structure & Properties of Substances
Homework 7
1a)
By means of a labelled diagram, show the experimental apparatus which
can be used to classify substances into conductors and non-conductors.
b)
Arrange the following solids into two columns headed conductors and nonconductors.
nickel, iodine, magnesium, sulphur, phosphorus
sodium, scandium, copper
c)
2
Arrange the following liquids into two columns headed conductors and
non-conductors.
Copper sulphate solution, silicon tetrachloride, liquid oxygen,
molten sulphur, sodium chloride solution, mercury, molten iron,
2.
1
3
A pupil investigated the properties of 3 compounds. The results are
shown in the table.
Substance
A
B
C
Melting point
high
low
high
Electrical conduction
Does not conduct in any state
Does not conduct in any state
Conducts in solution and as a melt
Using the information in the table explain whether the bonding in A,B and C is
discrete covalent (small molecule) , covalent network or ionic.
3
3.
Copy and complete the table.
Type of
structure
Ionic
Discrete
covalent
Covalent
network
Metallic
Physical state at room
temperature
Conductivity in
liquid state
Conductivity
in solid state
✓
Gas, liquid or soft solid
x
x
3
solid
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