1. Isotope: Same element (same number of protons) but with different number of neutrons. Same # of Protons Different amount of Neutrons We know these are both nuclei of Carbon because they each contain 6 protons. (red)

2. Ion: + or – charged atom; the atom has less or more electrons Sodium has 11 protons and 11 electrons making it neutrally charged. However, Sodium wants to have a full outer shell of 8 electrons. It is easier to give away it’s outermost electron This will give it 11 protons and 10 electrons; changing its charge to positive. Sodium will become a positive ion when it transfers its outermost electron to another element.

3. Valence: # of electrons needed to complete the outermost shell. Hydrogen has 1 proton and 1 electron. Since Hydrogen has only one shell, it needs only 2 electrons to be FULL. Therefore, Hydrogen’s valence is 1. Carbon has 6 protons and 6 electrons. 2 electrons fill the inner shell, leaving 4 electrons on the outer shell. Since Carbon needs 4 more electrons to be full…it has a valence of 4.

4. Covalent Bonding: The sharing of valence electrons; usually between nonmetals. The water molecule is a good example of covalent bonding between nonmetals. Oxygen has 8 protons and 8 electrons. 2 of the electrons load the first shell, 6 load the second shell….oxygen needs 2 more electrons to be FULL. Hydrogen has 1 proton and 1 electron. It needs only 1 more electron to FILL its outer shell. The two elements share their outermost electrons to complete each others outer shell.

5. Ionic Bonding: The transfer of electrons so that oppositely charged atoms(ions) bond; usually occurs between metals and nonmetals. + ion - ion Transfer of electron 11p 17p Sodium becomes a positive ion because it gives up its outermost electron (11p & 10e), Chlorine becomes negative because it gains an extra electron (17p & 18 e).