Chemistry - Atoms, Elements & Compounds

2.1 - 2.3

Elements

A substance that cannot be broken down into two or more simpler substances by chemical means

Compound

A substance made up of two or more elements - which are chemically combined

Mixture

A mixture is a substance that contains two or more substances that are no chemically combined / are physically combined

Atom

An atom is the smallest part of an element that can take part in a chemical reaction - it is made up of sub-atomic particles: protons, neutrons and electrons

Relative charge of a proton

+1

Relative charge of a neutron

0

Relative charge of an electron

-1

Relative mass of a proton

1

Relative mass of a neutron

1

Relative mass of an electron

1/1840

Location of a proton

Inside the nucleus

Location of a neutron

Inside the neucleus

Location of an electron

Outside the nucleus