Section 1: Key terms

Question 1

Atom

Answer 1

The smallest part of an element that can still be recognised as that element. No overall electric charge. Vey small, radius of 0.1nm.

Question 2

Element

Answer 2

An element contains only one type of atom. Found on the periodic table. There are about 100 elements.

Question 3

Compound

Answer 3

Two or more elements chemically bonded with each other.

Question 4

Mixture

Answer 4

Contains two or more elements or compounds not chemically bonded. Can be separated using physical methods. Examples: by filtration, crystallisation, distillation and chromatography.

Question 5

Filtration

Answer 5

A process that separates mixtures of insoluble solids and liquids.

Question 6

Crystallisation

Answer 6

A process that separates a soluble solid from a solvent by evaporating the liquid to leave crystals.

Question 7

Distillation

Answer 7

A process that separates a mixture of liquids based on their boiling points.

Question 8

Chromatography

Answer 8

A process that separates mixtures by how quickly they move through a stationary phase (e.g. paper chromatography)

Question 9

Relative atomic mass

Answer 9

An average value of mass that takes account of the abundance of the isotopes of the element.