Name: ________________________
60
SECTION A: MULTIPLE CHOICE (10 Marks)
Circle the correct response for each of the following questions:
1.
The smallest whole particle of an element is called:
a) an atom
c) a proton
b) a neutron
d) a compound
2.
The gas produced when hydrochloric acid (HCl) reacted with magnesium. The gas
produced in this reaction popped when lit. This presence of which particular gas is
indicated by a popping sound when lit?
a) helium
b) oxygen
c) hydrogen
d) carbon dioxide
3.
The formula of sodium hydroxide is Na OH. Sodium hydroxide is:
a) an element, it contains three different types of atoms
b) a compound it contains three different types of atoms
c) an element, it contains four different types of atoms
d) a compound it contains four different types of atoms
4.
The mass number of an element is the number of:
a) Protons in the nucleus of an atom of this element
b) Neutrons in the nucleus of an atom of this element
c) Protons plus neutrons in the nucleus of an atom of this element
d) Protons plus electrons in the nucleus of an atom of this element
5.
In the Periodic Table of Elements, most elements are
a) metals
b) colourless
c) liquids at room temperature
d) All of the above
6.
23
An atom represented by 12
Mg , there are
a) 12 protons, 12 electrons and 11 neutrons
b) 12 protons, 11 electrons and 12 neutrons
c) 11 protons, 11 electrons and 12 neutrons
d) 11 protons, 12 electrons and 11 neutrons
7.
Which of the following salts are likely to give the same flame colour as sodium chloride
when put in a flame?
a) lithium fluoride
c) potassium fluoride
b) copper chloride
d) sodium carbonate
8.
Positively charged particles that are found within the nucleus of an atom are called:
a) neutrons
c) protons
b) molecules
d) electrons
9.
Icecream goes soft and runny if left out of the fridge on a warm day. This is an
example of a
a) chemical reaction
c) evaporation
b) condensation
d) physical change
10.
When magnesium reacted with hydrochloric acid, bubbles were seen in the test-tube. This
is evidence that a chemical reaction has occurred and that
a)
the mixture is boiling
b) a suspension is forming
c) one of the products is a gas
d) one of the reactants is a gas
SECTION B: SHORT ANSWERS (35 Marks)
Answer all questions in the spaces provided:
1. Five diagrams, labelled v to z, are shown below. Use the letters v to z to answer the questions
that follow. Which diagram could represent:
a) an atom? __________
b) a single molecule? ________
c) a mixture of two different compounds? _________
d) molecules of a compound? _________
(4 marks)
2. State two important differences between a mixture and a compound:

_______________________________________________________________________________
_______________________________________________________________________________

_______________________________________________________________________________
_______________________________________________________________________________
(2 marks)
3. For each of the following, state whether it is a mixture (M), compound (C) or element (E).
a) soft drink
______
d) salt water
______
b) magnesium oxide powder ____
e) water
______
c) potassium metal ______
f)
______
helium gas
(1/2 x 6 = 3 marks)
4. Listed below are five atoms using symbols that are not the usual symbols of the elements. Use
the letters V to Z to answer the following questions.
40
18
V
20
10
W
40
19
X
39
19
Y
40
20
Z
a Which two atoms have the same number of neutrons? ___
b Which atom has the smallest mass number? __________
c Which two atoms belong to the same element? ___________
d Which two atoms have equal number of protons, neutrons and electrons?
_________
(4 marks)
5. Complete the table below showing details of the three main sub-atomic particles.
Particle
Charge
Location
proton
around the nucleus
neutral
(6 marks)
6.
Label all components of this diagram and name the element
+
+
Name of Element: __________________________
(5 marks)
7. Fill in the blank spaces for the table below
ELEMENT
SYMBOL
hydrogen
ELEMENT
lithium
C
Cl
helium
SYMBOL
Mg
argon
beryllium
K
P
O
silicon
N
Al
fluorine
sodium
(1/2 x 16 = 8 marks)
8.
When dilute acetic acid (vinegar) is mixed with sodium hydrogen carbonate (bicarb of
soda), bubbles of carbon dioxide gas are produced.
a) List one reactant in this reaction ___________________________
b) Is carbon dioxide an element or compound? ______________________
Explain your answer.
________________________________________________________________________________
________________________________________________________________________________
c) Other than bubbles being produced, list some other evidence that may indicate
that a chemical reaction has occurred.
___________________________________________________________________________
(4 marks)
9.
When sodium is added to water it fizzes quickly, and sometimes sparks are given off as
hydrogen gas and sodium hydroxide are formed.
Write a word equation to represent this reaction.
_____________________________________________________________________________
(1 mark)
10. Complete this table:
Name of
element
Symbol
Atomic
Number
Oxygen
16
Ca
20
F
Potassium
Mass
Number
Number of protons
Number
of
neutrons
8
40
19
19
Number of
electrons
10
20
(8 marks)
Section C: Data Analysis
1. Milk is a mixture of fat and water. When cooled and left to
stand, fat globules (bubbles) in raw milk rise to form a layer
of cream.
Homogenisation is the process of breaking up the fat
globules to such a size that they remain suspended evenly
in the milk rather than separating out and floating to the
surface.
The diagram (on the right) shows the fat globule formation
in three milk samples.
Which option places the diagrams in the order: raw milk, raw milk cooled and left to stand,
and homogenized milk (1 mark)?
A) X,Y,Z
B) X,Z,Y
C) Z,X,Y
D) Z,Y,X
(1 mark)
2. Metals are dense. They are malleable (can be bent without snapping) and they conduct
electricity. Non-metals are less dense. They are not malleable and they usually do not
conduct electricity
The table gives information about some substances:
Substance
Melting point
Colour
Density
Does it conduct
electricity?
Is it malleable?
(C)
tungsten
3410
bluish-grey
high density
yes
no
rhenium
3180
greyish-white
high density
yes
yes
graphite
3652
dark grey
low density
yes
no
copper
1083
reddish
high density
yes
yes
A) Which of the following substances is a non-metal?
____________________________________________________________________________________
B) Explain your choice, making reference to the data above
____________________________________________________________________________________
____________________________________________________________________________________
(2 marks)
3.
A molecule is the smallest part of a substance that contains all of its atoms. The
photographs show models of four molecules: ammonia (NH3), carbon tetrachloride (CCl4),
chloroform (CHCl3) and methanol (CH3OH). Please note: different shapes represent
different atoms.
Which drawing shows a chloroform molecule?
(2 marks)