All the questions on this page have featured in previous GCSE level exams at one point or another and this is a key topic - it will be in the exam. So check your answers against the markschemes and learn them! Remember foundation tier questions can also appear in the higher tier paper.
Q1: Which TWO of the diagrams below represent ions/ionic bonding?(2 marks) Click on the digram to find out if you're correct.
Q2: Name the compound shown in the diagram to the right. (1 mark)
Q3: The diagram to the right shows a fluorine atom. Draw a fluoride ion. (2 marks)
Marking points: 2 electrons in inner shell, 8 in outer shell (1 mark), correct charge in top right hand corner (1 mark)
Q4: The diagram to the right is a diagram of sodium chloride. Why do sodium ions attract chloride ions? (1 mark)
Q5: Explain why sodium chloride solution conducts electricity. (1 mark)
Q6: Which of the following elements, i) potassium, ii) beryllium or iii) chlorine, reacts with sodium to form an ionic compound?(1 mark)
Chlorine as it's the only non-metal on the list. For an ionic bond to form you need a metal (to donate electrons) and a non-metal (to gain electrons).
Q7: Sodium atoms react with chlorine atoms to form sodium chloride. This is shown in the diagram to the right. Describe this reaction in terms of electrons. (4 marks)
Q8: Magnesium reacts with oxygen to form magnesium oxide. State the charge on the ions formed. Use the diagrams to the right to aid you. (2 marks)
Oxygen has 6 electrons in its outer shell, therefore it gains 2 (negative) electrons to fill its shell giving it an overall charge of 2-. Magnesium loses 2 (negative) electrons when it forms an ion to give it an overall charge of 2+.
Diagram of an oxygen atom.
Diagram of a magnesium atom.
Q9: Read the sentence below, choose the correct missing word to fill in the gap from the following list i) attract, ii) repel, iii) positive, iv) negative. (1 mark)
Sodium chloride has a high melting point because oppositely charged ions _______ each other strongly. A large quantity of heat energy is required to overcome this attraction.
Attract (1). Remember opposite charges attract!
Q10: The diagram to the right shows the formation of sodium chloride. Explain why chlorine is being reduced. (2 marks)
Chlorine has gained (1) electrons (1) second mark often dependant on the first (i.e. you can't get the second mark unless you get the first one).
N.B. This question used to be higher tier only - it now appears in both tiers in the most recent syllabus.
Q11: The diagram to the right is a diagram of magnesium oxide. Determine its formula from the diagram.
MgO (1). The ratio of magnesium to oxygen is 1 to 1.
Pink = Magnesium ion
Yellow = Oxygen ion
Q12: Which of the following substances is bonded ionically. There may be more than one correct answer. (2 marks)
Q13: Under what conditions will sodium chloride conduct electricity. Explain your answer. (3 marks)
When molten (1) OR dissolved (1). The ions are free to move (1). .
AQA have changed what they will accept for the last marking point - be careful when looking at older mark schemes as they're out of date and poor use of scientific language/language which contradicts what's in the syllabus is no longer allowed.
Q14: Calcium carbonate has the formula CaCO3. The calcium ion has a charge of +2. Calculate the charge on the carbonate ion. (1 mark)
2- (1). The overall charge on the carbonate molecule is zero. So if the calcium ion has a charge of +2 the remainder of the molecule must have a charge of -2 to give a total of zero.
Q15: What is the formula of aluminium oxide? (2 marks)
Al2O3 (2). Aluminium is in group 3, so it has a charge of 3+, oxygen is in group 6 so it has a charge of 2-. Therefore 2 aluminium ions, whose total charge is 6+, and 3 oxygen ions, whose total charge is 6-, are needed to give an overall charge of zero.
Q16: Explain why sodium oxide has a high melting point. (4 marks)
It is a giant structure/lattice (1), with strong electrostatic forces of attraction (1) between oppositely charged ions (1) therefore a large quantity of energy is needed to overcome this attraction (1)
Q17: Sodium reacts with oxygen to form sodium oxide. Explain how oxidation and reduction have taken place in this reaction in terms of the movement of electrons.
Sodium is oxidised (1) as it loses electrons (1). Oxygen is reduced (1) as it has gained electrons(1). Remember OILRIG - Oxidation Is a Loss of electrons, Reduction Is a Gain of electrons.
Q18: Describe the structure and bonding in sodium chloride. (4 marks)
Lattice/Giant structure (1), contains ions (1), ions present are Na+ and Cl-(1), electrostatic attraction/opposite charges attract (1)