Ionic, Covalent & Metallic Bond (AQA GCSE Chemistry: Combined Science)

The arrangement of electrons in a sodium atom can be written as 2, 8, 1 which represents the atom's electronic structure.

Write the electronic structure for an atom of potassium.

The electronic structure of a sodium atom can also be shown using an electron shell diagram as shown in Figure 1.

Figure 1 

Repeat the drawing for a chlorine atom to show its electronic structure.

Draw a similar diagram to show the electronic structure of the particles in sodium chloride, indicating how the compound was formed.

The ionic lattice structure of sodium chloride is shown in the diagram.

Complete the table. 

Using the diagram in (a) to help you, describe the nature of the chemical bonding in ionic structures.

Suggest two assumptions that the diagram in part (a) makes.

Calcium metal combusts in oxygen and produces calcium oxide, CaO.

Balance the equation for the reaction. 

___Ca(s) + ___O₂(g) → ___CaO(s)

Describe what happens when a calcium atom becomes ionised.

Magnesium iodide is an ionic compound containing magnesium ions (Mg²⁺ ) and iodide ions (I^–).

State the chemical formula of magnesium iodide.

Describe, in terms of electrons and bonding, the reaction between magnesium and iodine.

Ammonia, NH₃, is a small covalent molecule.

How many non-bonding, outer-shell electrons are present in one molecule of ammonia?

Iodine and bromine are both halogens. The bonding in iodine is similar to the bonding in chlorine.

Suggest two reasons why they bond in similar ways.

Complete the diagram below to show the bonding arrangement in a molecule of iodine.

Show the outer shell electrons only.

Explain why liquid iodine is unable to conduct electricity.

Zinc is a typical metal.

Describe the structure and bonding in zinc.

Explain how zinc is able to conduct electricity?

The surface of some metals, such as iron and copper, corrode when exposed to the air which reduces their electrical conductivity. 

Suggest why their conductivity is reduced.

Magnesium ribbon is used in many school laboratories for carrying out reactions involving metals and acids. It can be cut and folded easily. 

Explain why metals can be bent and shaped.

Elements can bond together in many different ways, by sharing, gaining or losing electrons. In some of the resulting structures, strong electrostatic forces of attraction occur as a result of the type of bonding.

Which of the following examples does not involve strong electrostatic forces of attraction?

This question is about covalent bonding.

Write down four differences between ionic compounds and simple covalent compounds.

Describe the bonding in a molecule of ammonia, NH₃.

This question is about sodium oxide.

Describe the structure and bonding in sodium oxide. 

Sodium is in Group 1 of the periodic table and oxygen in Group 6. 

What is the formula of sodium oxide?

Draw dot and cross diagrams to represent the three ions formed by sodium oxide. 

Figure 1 shows two other way of representing ionic compounds.

Compare the advantages and limitations of each model.

This question is about chemical bonds.

Aluminium and chlorine react to form aluminium chloride. 

Write the balanced symbol equation for the reaction.

Include state symbols.

Describe, in terms of electron arrangement, the type of bonding in a molecule of chlorine.

Describe, in terms of electron arrangement, the type of bonding in the compound aluminium chloride.

This question is about covalent bonding.

What is a covalent bond?

Complete the dot and cross diagram to show the bonding in propane. 

Explain why propane cannot conduct electricity.

Give two limitations of the dot and cross diagram in part (b).

This question is about the properties of metals. 

Copper is a typical metal.

Explain how the particles in copper are held together and why the metal is malleable.

You may use a diagram in your answer. 

Metals are good conductors of electricity.

Electrical conductivity increases across Period 3, from sodium to aluminium.

Explain why. 

This question is about structure and bonding.

Complete the dot and cross diagram to show the covalent bonding in an oxygen molecule, O₂.

Show only the electrons in the outer shell.

Oxygen can react with magnesium to form magnesium oxide.

Describe the differences in the bonding and structure of magnesium oxide and oxygen. 

The melting points of magnesium oxide and sodium chloride are shown in Table 1. 

Table 1 

Explain why magnesium oxide has a higher melting point than sodium chloride.