Covalent Bonding: Answers

 Define the term ‘covalent bond’.

A covalent bond is formed when two atoms share electrons. It is the electrostatic attraction between positive nuclei and the shared pair of electrons.

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

Simple covalent molecules have low melting and boiling points because they have weak intermolecular forces between them which break when these molecules change state.

Why do giant covalent structures have high melting and boiling points?

Giant covalent structures have high melting and boiling points because the strong covalent bonds between atoms need to break when they change state.

Give the feature of graphite which allows it to conduct electricity.

Graphite has delocalised electrons between its layers which are charged and free to move. Anything that moves and has charge is able to conduct electricity.

Give the feature of graphite which allows it to function as a lubricant.

The layers within graphite are held together by weak intermolecular forces which are easily broken, allowing the layers to slide over one another. This made graphite slippery and allows it to function as a lubricant.