Yr 8 Science

2. a row in the periodic table
4. drugs that are taken for enjoyment
5. an element from group 7 of the periodic table
8. a characteristic that makes an organism better suited to living in its environment
12. substances such as those in cigarettes which cause cancer
14. a substance that has dissolved in a solvent
15. an animal that eats just plants
17. an example of anerobic respiration
19. the process by which sugars are made using carbon dioxide and water in the presence of sunlight
20. a column in the periodic table
21. the repeating unit in a polymer
22. fats and oils

1. a method used to separate two liquids with different boiling points
3. Darwin's theory that explains why populations change with time
5. the elements of group 7 in the periodic table
6. a type of chemical reaction where a more reactive element takes the place of a less reactive element in a compound
7. the molecule that carries oxygen around the body
9. biological catalysts that help break down food in the gut
10. genetic material
11. we have 46 of them in most cells in our body
13. the idea that organisms in a food web depend on each other for survival
16. hard brittle materials that break easily when stretched
18. the type of respiration for which oxygen is required
23. the chemical we use to test for starch