Across
- 2. Positively charged, massive, located in the nucleus
- 3. Tells us how many atoms of each element are in a molecule.
- 5. Occur when two or more DIFFERENT types of atoms combine together to form molecules.
Down
- 1. Located on the left side of the periodic table.
- 2. After the change the mass always has to be the same.
- 4. On the periodic table they have similar properties