| A | B |
|---|
| element | a pure substance that cannot be broken down into simpler substances |
| compound | a pure substance that is composed of two or more atoms |
| atom | the smallest particle of any element that retains the properties of the element |
| chemical changes | changes in the ways the atoms in a pure substance are arranged |
| subatomic particles | particles that make up an atom |
| protons | subatomic particles with a positive charge |
| neutrons | subatomic particles with no electric charge |
| electrons | subatomic particles that have a negative charge |
| nucleus | centre of an atom made of protons and neutrons |
| nuclear charge | electric charge of the nucleus |
