GCSE Combined Science Bonding & structure questions by topic

Name each change of state.

1. (a)Solid to liquid.[1]
2. (b)Gas to liquid.[1]
3. (c)Liquid to gas at the surface only.[1]
4. (d)Solid straight to gas.[1]

Magnesium chloride contains Mg²⁺ and Cl⁻ ions.

1. (a)Explain how a magnesium atom becomes Mg²⁺.[2]
2. (b)Write the formula of magnesium chloride.[1]
3. (c)Name the force holding the lattice together.[1]

Match each molecule to its number of shared pairs.

1. (a)State the number of shared pairs in H₂, H₂O, NH₃ and CH₄.[4]

Explain the arrangement of particles in the three states of matter.

1. (a)Describe the arrangement and movement of particles in a solid.[2]
2. (b)State one difference between the particles of a gas and those of a liquid.[2]

Compare the melting points and conductivity of sodium chloride and paraffin wax (a simple molecular substance).

1. (a)Compare their melting points and explain the difference.[2]
2. (b)State which substance conducts electricity when molten, and why the other does not.[2]

Copper is used for electrical wiring; brass (a copper-zinc alloy) is used for hard-wearing door fittings.

1. (a)Explain why copper conducts electricity.[2]
2. (b)Explain why brass is harder than pure copper.[2]

This question is about drawing covalent structures.

1. (a)Draw a dot-and-cross diagram for ammonia (NH₃).[2]
2. (b)State how many electrons are in nitrogen’s outer shell after bonding, and name the pair not used in bonding.[2]

Explain the differences between diamond and graphite.

1. (a)State how many bonds each carbon atom forms in diamond and in graphite.[2]
2. (b)Explain why graphite conducts electricity but diamond does not.[2]
3. (c)Give one use of graphite that follows from its layered structure.[1]

A materials scientist must choose between graphene and diamond for a new flexible electronic screen.

1. (a)Explain which allotrope suits the screen and why, using structure.[3]
2. (b)Give two properties of graphene that support your choice.[2]
3. (c)State one limitation of graphene-based technology today.[1]

Explain, in terms of structure and bonding, the differences in boiling temperature between water and sodium chloride.

1. (a)Describe the particles present in each liquid.[2]
2. (b)Explain why sodium chloride boils at a far higher temperature.[3]
3. (c)State what happens to the covalent bonds inside water molecules when water boils.[1]

A student writes: “Table salt conducts electricity, so it must contain free electrons.”

1. (a)Explain the error in this claim.[2]
2. (b)Describe the correct conditions under which salt solution conducts, and name the particles that move.[2]

Buckminsterfullerene (C₆₀) and graphene both contain only carbon.

1. (a)Name the relationship between these two substances and define it.[2]
2. (b)Suggest why C₆₀ dissolves more easily than graphite, using their structures.[2]