Across
- 2. When a reaction lets off heat
- 4. ________ electrons are on the outer most shell
- 6. what does two hydrogen and one oxygen molecule make
- 7. Bonds that share a Valance electrons in two elements are called __________ bonds
- 8. This contains three basic particles-protons, Neutrons, and electrons.
- 9. A group of atoms held together with chemical bonds.
Down
- 1. Chemical ______ is all the elements in a thing shown
- 3. When a reaction takes in heat
- 5. Chemical ____ are the links between atoms in a substance that determines its identity
- 7. A chemical ______ is change that happens that change the thing at a molecular level.