Chemistry

2. the basic unit of a chemical element.
5. an uneven distribution of electric charge within a molecule or bond
8. the electrons in the outermost shell, or energy level, of an atom
10. results from the transfer of electrons from a metal to a non-metal to obtain a full valence shell for both atoms
12. the degree to which an element tends to gain electrons and form negative ions in chemical reactions.

1. an atom of the same element that has a different number of neutrons
3. relating to or resembling metal or metals.
4. made when two or more atoms join together through chemical bonds
6. association of atoms or ions to form molecules, crystals, and other structure
7. describes how much mass is packed into a certain amount of space
9. relating to or denoting chemical bonds formed by the sharing of electrons between atoms
11. is a unit used to measure energy in chemistry and physics