Chemistry Vocabulary

3. A chemical reaction that releases heat energy.
4. A chemical reaction that absorbs heat energy.
7. The new substances formed in a chemical reaction.
10. A short way to show what elements are in a compound and how many of each there are.
11. Two or more substances that join together.
12. The substances you start with in a chemical reaction.
15. Bonds formed by the attraction between positively and negatively charged ions
16. Things that make up everything around us.

1. When substances change into different ones.
2. Bonds formed when atoms share electrons.
5. Small numbers written to show how many atoms of each element are in a compound
6. Natural materials are things that come from nature, like wood or cotton. Synthetic materials are made by people, like plastic or nylon.
8. Heat energy.
9. The idea that matter cannot be created or destroyed in a chemical reaction, only rearranged.
11. Substances that make chemical reactions happen faster.
13. Pure substances made up of only one type of atom.
14. Numbers written in front of chemical formulas to balance equations.