Across
- 3. Substances that cannot be chemically broken down into simpler substances.
- 5. the smallest particle that can exist.
- 7. This causes global warming.
- 9. Two different elements chemically joined.
- 10. 78% of the air is made from ……..
- 11. A group of atoms chemically bound together.
- 13. An atom with electric charge.
- 14. opposite to endothermic
- 16. A reaction between iron, water and oxygen.
Down
- 1. A way of preventing rust by coating steel or Iron in zinc.
- 2. this has three things in it without one there is no reaction.
- 4. One substance meets another substance without a chemical reaction.
- 6. This is a greenhouse gas
- 8. A reaction that takes in energy and makes surroundings cooler.
- 12. We need this to live.
- 15. A rapid reaction that gives out energy.