Across
- 5. An old model of the atom, proposed by JJ Thompson. It was a ball of positive charge, with electrons dispersed inside it.
- 7. The number of protons in the nucleus of an atom. Also called proton number.
- 9. 2 or more different elements, in fixed proportions, chemically bonded together.
- 11. Atoms of the same element with different numbers of neutrons
- 13. Elements that react to form positive ions.
- 14. 2 or more different elements or compounds, which can be separated by physical means.
Down
- 1. The horizontal rows of the periodic table.
- 2. The model of the atom proposed by Rutherford. A small, dense, positive nucleus is in the centre, and electrons orbit this.
- 3. A substance containing a single type of atom.
- 4. A charged particle formed when an atom has lost or gained electrons.
- 6. Reaction A reaction where a more reactive element displaces (replaces) a less reactive element from its compound e.g. Iron + Copper sulphate Copper + Iron sulphate
- 8. The total number of protons and neutrons in the nucleus of an atom.
- 10. Elements that do not form positive ions.
- 12. The vertical columns of the periodic table