Topic 2: Bonding, Structure and the Properties of Matter

What are the three types of strong chemical bonds?

Ionic, covalent, and metallic bonds.

What happens in ionic bonding?

Electrons are transferred from a metal to a non-metal forming oppositely charged ions.

What is a covalent bond?

A bond formed when two atoms share pairs of electrons.

What is metallic bonding?

Positive metal ions surrounded by a sea of delocalised electrons.

Why do ionic compounds have high melting points?

Due to strong electrostatic forces between oppositely charged ions in all directions.

Why do small covalent molecules have low melting points?

They have weak intermolecular forces that require little energy to overcome.

What are polymers?

Large molecules made from repeating covalently bonded units.

Why are giant covalent structures strong?

All atoms are bonded by strong covalent bonds throughout the lattice.

Why do metals conduct electricity?

Delocalised electrons move freely through the structure.

What is an alloy and why is it harder than pure metal?

A mixture of metals with distorted layers, making it harder for atoms to slide.

How does particle theory explain state changes?

It shows particles gain energy to overcome intermolecular forces during melting or boiling.

What are state symbols for solid, liquid, gas, and aqueous?

(s), (l), (g), and (aq).

Describe the structure of diamond.

Each carbon bonded to four others in a giant covalent structure; very hard and does not conduct electricity.

Describe the structure of graphite.

Layers of carbon atoms each bonded to 3 others, with delocalised electrons and weak forces between layers.

Why can graphite conduct electricity?

It has delocalised electrons that move through the structure.

What is graphene?

A single layer of graphite; strong, light, and conducts electricity.

What are fullerenes?

Molecules made of carbon atoms arranged in hollow shapes like spheres (e.g. C₆₀).