Chemistry refresher

5. Red litmus paper must be ____ when testing for ammonia gas
7. (2 words) A giant covalent structure that has similar properties to diamond based on its structure
10. The colour of damp blue litmus paper in presence of chlorine gas
11. What type of compound is lithium oxide?
13. (2 words) Another name for the test of hydrogen gas
14. This substance turns cloudy when testing for carbon dioxide
16. To reduce a metal from its ore, it needs to be _____ carbon in the reactivity series.
18. A substance that can behave either as an acid or a base is also known as _____
19. A bond formed where there is a force of attraction between positive nuclei and a shared pair of electrons
21. When a species either loses oxygen or gains electrons
22. When testing for the presence of the ammonium ion or nitrate ion, you need to form this gas to produce a positive result with damp red litmus paper

1. The colour of the precipitate formed when testing for the bromide ion
2. The colour of of the flame when sodium is tested
3. When a species either gains oxygen or loses electrons
4. A term used to describe the free movement of electrons in a metal or in graphite
6. An insoluble chemical produced during a chemical reaction
8. Initially forms a white precipitate but then redissolves in excess NaOH and NH3
9. All nitrate compounds are _____ in water
12. (2 words) Identify the compound from the following tests: 1) When added to dilute NaOH, a white precipitate forms. Adding excess NaOH has no effect. Adding NH3 has little to no effect. 2) When added to dilute aqueous NaOH in presence of aluminium foil and heated gently, damp red litmus paper turns blue.
15. Copper(II) redissolves in excess NH3 to form a deep blue solution due to the formation of a _____ ion
17. When a metal reacts with acid in needs to be _____ hydrogen in the reactivity series
20. (2 words) A chemical added to the test for halide ions and sulfate ions to react with any impurities so that it makes them soluble
23. Different forms of an element