Diamond and graphite | Exit Quiz | Oak National Academy

What is an allotrope?

• a type of chemical bond

• a different structural form of an element

• a kind of molecular geometry

• a category of organic compounds

Answer explanation

An allotrope is a different structural form of an element, like graphite and diamond are allotropes of carbon.

What makes diamond so hard?

• intermolecular forces

• delocalised electrons

• hexagonal rings

• covalent bonds

Answer explanation

Diamond's hardness comes from its giant covalent structure, where each carbon atom is bonded strongly to four others.

Why can graphite be used as a lubricant?

• strong covalent bonds within atoms

• weak intermolecular forces between layers

• delocalised electrons

• high melting point

• ability to conduct electricity

Answer explanation

Graphite's layers can easily slide over each other due to the weak intermolecular forces between them, making it a good lubricant.

In diamond, each carbon atom forms (a)   covalent bonds.

Answer explanation

In diamond, each carbon atom forms four covalent bonds, creating a very strong and rigid structure.

True or false? In graphite, each carbon atom is bonded to four other carbon atoms.

• True

• False

Answer explanation

In graphite, each carbon atom is covalently bonded to three others, forming layers of hexagonal rings.

Graphite conducts electricity because it has (a)   which can move and carry charge/current.

Answer explanation

Graphite conducts electricity because it has delocalised electrons which can move and carry charge/current.