AQA GCSE Chemistry (Triple) - Bonding, Structure and the Properties of Matter

Flashcards covering key concepts within 'Bonding, Structure and the Properties of Matter' for AQA GCSE Chemistry.

What are the three main types of chemical bonding?

Ionic, covalent, and metallic bonding.

What type of elements form ionic bonds?

Metals and non-metals.

Describe what happens in ionic bonding.

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

What is the structure of an ionic compound?

A giant ionic lattice with strong electrostatic forces between oppositely charged ions.

Why do ionic compounds have high melting and boiling points?

A lot of energy is needed to overcome the strong electrostatic forces between ions.

Why do ionic compounds conduct electricity when molten or in solution but not when solid?

Ions are free to move and carry charge only when molten or dissolved.

What type of elements form covalent bonds?

Non-metals.

Describe a covalent bond.

A shared pair of electrons between two atoms.

Why do simple covalent molecules have low melting and boiling points?

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

Why don’t covalent substances conduct electricity?

They have no delocalised electrons or ions to carry charge.

Name four substances with giant covalent structures.

Diamond, graphite, graphene, and silicon dioxide.

Why is diamond hard?

Each carbon atom is covalently bonded to four others in a rigid 3D structure.

Why does graphite conduct electricity?

It has delocalised electrons that move between layers.

How are graphite layers held together?

By weak intermolecular forces.

What is graphene?

A single layer of graphite with a hexagonal structure of carbon atoms.

Give one use of fullerenes or carbon nanotubes.

Used in drug delivery, catalysts, or reinforcing materials.

Describe metallic bonding.

Positive metal ions surrounded by a sea of delocalised electrons.

Why do metals conduct electricity and heat?

Delocalised electrons can move freely through the structure.

Why are metals malleable and ductile?

Layers of atoms can slide over each other without breaking bonds.

Why are alloys harder than pure metals?

Different-sized atoms distort layers, making it harder for them to slide.

Describe the arrangement of particles in solids, liquids, and gases.

Solids: fixed, regular; Liquids: close but random; Gases: far apart and move randomly.

What happens during a change of state?

Energy is transferred to or from the substance to overcome or form intermolecular forces.

Why does temperature remain constant during melting or boiling?

Energy is used to break intermolecular bonds, not to increase kinetic energy.

What size are nanoparticles?

Between 1 and 100 nanometres.

Why are nanoparticles more reactive than bulk materials?

They have a very large surface area to volume ratio.

Give two potential uses of nanoparticles.

Sunscreens, drug delivery, catalysts, or deodorants.

Give one risk of using nanoparticles.

They may be toxic or cause unknown effects in the body or environment.