C1 Atomic Structure

4. substances are separated by running a solvent along a material such as absorbent paper
6. atoms that have the same number of protons but different number of neutrons,
9. the mixture made by adding a soluble substance to water
11. a substance made up of only one type of atom.
12. a substance we start with before a chemical reaction takes place
14. all the elements in the columns (labelled 1 to 7 and 0) in the periodic table
17. the very unreactive gases found in Group 0 of the periodic table.
19. the number of protons (which equals the number of electrons) in an atom.
20. the very small and dense central part of an atom that contains protons and neutrons
21. the smallest part of an element that can still be recognised as that element

1. an arrangement of elements in the order of their atomic numbers, in a table.
2. a substance made as a result of a chemical reaction.
3. fuel made from animal or plant products
5. It is electrically neutral, carrying no charge
7. a structure in numbers to show the arrangement of electrons in their shells (or energy levels)
8. an area in an atom, around its nucleus, where electrons are found
10. a charged particle produced by the loss or gain of electrons
13. a substance made when two or more elements are chemically bonded together
15. a tiny particle with a negative charge
16. a tiny positive particle found inside the nucleus of an atom
18. the number of protons plus neutrons in the nucleus of an atom