AQA GCSE Chemistry (8462), Higher tier · Atomic structure and the periodic table › Atoms, isotopes and electronic structure
Practise Atoms, elements and compounds. 11 exam-style questions on this subtopic, at up to four difficulty levels, with full mark schemes and a progress tracker. Free, no account needed.
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Chalk is mainly calcium carbonate. The formula of calcium carbonate is CaCO3. Give the chemical symbol for calcium.
Ca
Lithium is the only Group 1 metal that reacts with nitrogen at room temperature. The product is lithium nitride, Li3N. Write a word equation for the reaction.
lithium + nitrogen → lithium nitride
A student added zinc powder to silver nitrate solution. Silver and zinc nitrate solution were produced. Zn + ....AgNO3 → Zn(NO3)2 + ....Ag Balance the equation.
Zn + 2AgNO3 → Zn(NO3)2 + 2Ag
Chlorine gas can be made in a fume cupboard by reacting potassium manganate(VII), KMnO4, with concentrated hydrochloric acid. ....KMnO4 + ....HCl → ....KCl + ....MnCl2 + ....Cl2 + ....H2O Name the compound with the formula MnCl2.
manganese chloride / manganese(II) chloride
When a mixture of aluminium powder and iron(III) oxide is ignited, it glows white hot and molten iron is formed. 2Al + Fe2O3 → Al2O3 + 2Fe Name the compound Al2O3.
aluminium oxide
The iron filings in the mixture were attracted to the magnet. Explain why.
The iron and sulfur are not chemically combined, so the iron keeps its magnetic property.
Sample questions
Written for this site in the style of AQA exam questions. They are not taken from real past papers.
Question 1Easy5 marks
Chalk is mainly calcium carbonate. The formula of calcium carbonate is CaCO3.
(a) Which of these substances is an element? Tick (✓) one box.[1]
Carbon dioxide
Magnesium
Sodium chloride
Water
(b) Give the chemical symbol for calcium.[1]
(c) Name the three elements in calcium carbonate.[1]
(d) How many atoms are shown in the formula CaCO3?[1]
(e) Which statement describes an atom? Tick (✓) one box.[1]
A particle that always has an overall positive charge
The smallest part of an element that can exist
Two or more elements chemically combined
A substance that contains more than one type of particle
Show the answer and mark scheme
(a)Answer: Magnesium
(b)Answer: Ca
Ca
(c)Answer: calcium, carbon and oxygen
calcium, carbon and oxygen
(d)Answer: 5
5
(e)Answer: The smallest part of an element that can exist
Question 2Medium5 marks
Lithium is the only Group 1 metal that reacts with nitrogen at room temperature. The product is lithium nitride, Li3N.
(a) Write a word equation for the reaction.[1]
(b) Balance the symbol equation for the reaction. ....Li + N2 → ....Li3N[1]
(c) Compounds contain elements in fixed proportions. Give the ratio of lithium atoms to nitrogen atoms in lithium nitride.[1]
(d) Explain why lithium nitride can only be separated into lithium and nitrogen by a chemical reaction.[2]
Show the answer and mark scheme
(a)Answer: lithium + nitrogen → lithium nitride
lithium + nitrogen → lithium nitride
(b)Answer: 6Li + N2 → 2Li3N
6Li + N2 → 2Li3N
(c)Answer: 3 : 1
3 : 1
(d)Answer: The lithium and nitrogen are chemically combined (bonded); physical processes such as filtration or distillation cannot break these bonds.
the elements / lithium and nitrogen are chemically combined / bonded
physical processes (such as filtration or distillation) cannot separate them / bonds must be broken (by a chemical reaction)
Question 3Hard6 marks
A student added zinc powder to silver nitrate solution. Silver and zinc nitrate solution were produced. Zn + ....AgNO3 → Zn(NO3)2 + ....Ag
(a) Balance the equation.[1]
(b) Zinc nitrate is an ionic compound. Give the formulae of the two ions in zinc nitrate.[2]
(c) The nitrate ions do not change during the reaction. Write the ionic equation for the reaction.[2]
(d) Complete the half equation for the change to the silver ions. Ag+ + .......... → Ag[1]