Section 1: Atomic structure and the periodic table
Atoms, elements and compounds 1.
Which of these are compounds? Tick two boxes.
2.
Air
Carbon dioxide
Iron
Water
[2 marks]
Define the word ‘element’.
Command words [1 marks]
3.
A teacher heats a piece of sodium and adds it to a gas jar containing chlorine. a Give the chemical symbols for sodium atoms and
chlorine molecules.
Sodium atoms
Chlorine molecules
[2 marks]
‘Define’ means to state the meaning of something. In this question you need to say what an element is.
Command words When you are asked to ‘give’ an answer you only need to write a short answer, not an explanation or a description.
Remember
Command words
Elements and their symbols are listed on the periodic table. You will be supplied with a periodic table in the exam.
The command word ‘name’ asks you to answer with a single word, phrase or sentence.
Some elements exist as molecules. For example, the gases hydrogen, nitrogen, chlorine and oxygen exist as pairs of atoms.
b Name the compound formed in the reaction.
[1 mark]
c How could the compound be separated back into its elements?
Tick one box.
Dissolving in water
Distillation
Heating
Using a chemical reaction
[1 mark]
4
257842 GCSE Chemistry Grade 67 Booster Workbook_Ch01.indd 4
10/24/18 3:58 PM
1
Mixtures 1.
Draw one line from each mixture to the most appropriate separation method.
Worked Example
2.
Mixture
Separation method
Different coloured inks
Add water then filter
Water and ethanol
Chromatography
Salt and water
Crystallisation
Sand and salt
Distillation
[3 marks]
A student carried out the following experiment. A Measure 1.6 g of iron powder and add it to a test tube. B Measure 0.4 g of sulfur and add it to the test tube. Mix well.
C Heat the test tube and contents over a Bunsen burner until an orange glow is seen
inside the test tube.
a In step C the student should plug the end of the test tube with mineral wool.
Suggest why the student should do this.
b In which step does the test tube contain a pure element?
Synoptic
Tick one box.
A
B
C
[1 mark]
c Suggest a method the student could use to separate the
mixture formed in step B.
[1 mark]
Command words When a question asks you to ‘suggest’ something it expects you to use your understanding in what may be an unfamiliar situation.
[1 mark]
[2 marks]
d Explain how the method you gave in part c works.
5
257842 GCSE Chemistry Grade 67 Booster Workbook_Ch01.indd 5
10/24/18 3:58 PM
3.
Ethanol and methanol are both liquids.
Command words
T he boiling point of ethanol is 78 °C. The boiling point of methanol is 65 °C.
When you are asked to ‘explain’ something you need to state the reasons for it happening.
ame the separating technique you would use to separate N a mixture of ethanol and methanol.
Command words
Describe how the separating technique works.
In this question you are being asked to ‘describe’ the processes that happen during the technique.
[5 marks]
Compounds, formulae and equations 1.
The diagram shows a molecule of fructose, a simple sugar. Fructose contains carbon, hydrogen and oxygen.
[2 marks] 2.
C HO
Write the formula of fructose.
O
CH2OH
H
H
OH C
C
C
OH
CH2OH H
Name the following compounds. a LiCl
[1 mark]
[1 mark]
[1 mark]
[1 mark]
b Na2CO3
c BaSO4
d Ca(OH)2
6
257842 GCSE Chemistry Grade 67 Booster Workbook_Ch01.indd 6
10/24/18 3:58 PM
1 Here are some tips for writing symbol equations. Use the periodic table to look up the symbols of elements. Elements that are gases at room temperature (other than the Group 0 elements) exist as pairs. For example, oxygen is O2. Symbol equations must be balanced. However, you can only change the numbers in front of each formula. You may be asked to provide state symbols (s, l, g, aq). 3.
Magnesium reacts with oxygen when it is heated. Complete the word and symbol equations to show this reaction. Include state symbols. magnesium + oxygen → 2 ____(s) + ____(____) → ____MgO (s)
[4 marks]
Scientific models of the atom 1.
The diagram shows a model of the atom called the nuclear model. Name the structures labelled X, Y and Z.
X +
X
+
Y
Y Z 2.
[3 marks]
Z
An earlier model of the atom was the ‘plum pudding’ model. Compare the plum pudding model with the nuclear model shown above.
Command words When you are asked to ‘compare’ things you need to write about the similarities and/or differences between them, not just write about one of the things.
257842 GCSE Chemistry Grade 67 Booster Workbook_Ch01.indd 7
[6 marks]
7
10/24/18 3:58 PM