Pure substances Flashcards – AQA GCSE Combined Science: Trilogy (8464) — Chemistry — Foundation

How does a pure substance melt and boil?

At specific temperatures characteristic of the substance.

How can a measured melting point or boiling point be used to judge a sample’s purity?

Compare it with the known value: a match is consistent with purity; a difference indicates an impure sample or mixture.

What is a pure substance in chemistry?

A substance made of one kind of particle: a single element or compound, with no other substance mixed in.

What type of atoms does a pure element contain?

Only one type of atom.

What does a pure compound contain?

Only one type of chemically bonded substance.

How does chemical purity differ from the everyday meaning of purity?

Chemical purity means being a single substance. Everyday purity can mean natural or having nothing added, even if the material is a mixture.