Exam practice
Exam questions
Write your answer. Then open the mark scheme and tick each point you made.
- Question 1 of 101 mark
State what is meant by an element.
Mark scheme
- A substance made of only one type of atom
- Question 2 of 102 marks
Give two ideas from Dalton’s model of the atom.
Mark scheme
- All matter is made of atoms
- Atoms are like tiny solid balls (accept: spheres)
- Atoms cannot be broken down into anything simpler
- All the atoms of one element are identical (accept: atoms of different elements are different)
- Question 3 of 103 marks
Write the chemical symbols for (a) magnesium, (b) iron and (c) chlorine.
Mark scheme
- (a) Mg
- (b) Fe
- (c) Cl
- Question 4 of 101 mark
Give one reason why scientists use chemical symbols.
Mark scheme
- They are quicker to write than names (accept: scientists in every country use the same symbols, whatever language they speak)
- Question 5 of 102 marks
State what is meant by a compound.
Mark scheme
- A substance made of two or more elements (accept: two or more types of atom)
- That are chemically joined together (accept: bonded)
- Question 6 of 102 marks
Sodium is a soft, shiny metal. Chlorine is a poisonous green gas. They react to make sodium chloride. Describe sodium chloride, and state what this shows about compounds.
Mark scheme
- White crystals (accept: a white solid; table salt)
- A compound has different properties from the elements it is made of
- Question 7 of 103 marks
A student stirs iron filings and sulfur powder together. A magnet pulls the iron out. She then heats a fresh mixture until it reacts, and a black solid forms. A magnet does not pull any iron out of the black solid. Explain these two results.
Mark scheme
- Before heating it is a mixture: the iron and the sulfur are not joined (accept: each keeps its own properties, so the iron is still magnetic)
- Heating makes a compound (accept: iron sulfide; a new substance)
- In the compound the iron atoms are joined to sulfur atoms, and the compound is not magnetic (accept: the compound has different properties from iron)
- Question 8 of 103 marks
The formula of carbon dioxide is CO2. (a) Name the two elements in carbon dioxide. (b) State how many atoms of each element there are in one molecule.
Mark scheme
- (a) Carbon and oxygen
- (b) One carbon atom
- (b) Two oxygen atoms
- Question 9 of 102 marks
Name the compound made when (a) magnesium reacts with oxygen, and (b) iron reacts with sulfur.
Mark scheme
- (a) Magnesium oxide
- (b) Iron sulfide
- Question 10 of 103 marks
The diagrams show the particles in three substances. Each circle is an atom. State which diagram shows (a) an element, (b) a compound and (c) a mixture.
Mark scheme
- (a) B
- (b) C
- (c) A