Chemistry Crossword

3. A particle located in the nucleus with a positive charge
4. Formed when two atoms share one or more pairs of electrons
5. The basic unit of all matter
8. Any group of atoms that form either a positive or negative net charge
9. A pure substance that cannot be chemically broken down
11. Any electron that is located in the outer shell of the atom
13. A variant of a certain element, caused by a change in the number of neutrons
14. A negatively charged particle with little mass and high amounts of energy
15. The center of an atom that holds most of it's mass

1. Particles without a charge
2. The graph that states every element and their properties
6. A group of atoms bonded together that make up the smallest unit in a chemical compound.
7. A substance made up of atoms from two or more elements
10. Credited with the creation of the periodic table
12. Any substance that has mass and takes up space