Year 9 Elements

2. a substance that contains two or more different types of atoms that are chemically joined
4. gas this is a flammable gas but is also used for respiring in living things, can be distinguished with a glowing splint test
7. the horizontal rows that tell us how any electron shells there are
10. the basic unit of matter
12. a negatively charged subatomic particle found in shells around the nucleus
13. number the number on the periodic table that tells us the number of protons in an atom
15. a neutrally charged subatomic particle found in the nucleus
17. the substances that react together (the ingredients)
18. this kind of change involves turning reactants into products, making new substances which means it is not easily reversible

1. a substance that contains two or more different elements or compounds that are not chemically joined together
3. this kind of change only involves changing state and now new substances are made - it is easily reversible
5. a highly flammable gas that is less dense than air, can be distinguished with a pop test
6. a positive subatomic particle found in the nucleus
8. a substance containing only one type of atom
9. the substance produced in a chemical reaction
10. this symbol must be used between reactants and products to show a reaction
11. number the number on the periodic table that tells us the number of protons and neutrons added together
14. a gas that is a product of respiration and also used in fire extinguishers, can be tested with limewater
16. the vertical columns on the periodic table that tell us how many valence electrons there are