1. Ion a particle that is electrically charged (positive or negative); an atom or molecule or group that has lost or gained one or more electrons Ions DO NOT ADD OR LOSE PROTONS

2. What does the charge of an Ion mean? It is the number of electrons that the atom has added or lost. For example, if a Hydrogen atom gains an electron it would become negatively charged (H -1 )

3. How to find the number of electrons in an ion. Find how many protons or electrons in would have as a nuetral atom. Then what ever the charge is (i.e. positive) do the opposite of the charge (subtract) to the electrons only Cl +2 = 17 electrons -2 electrons = 15e

4. Isotope one of two or more atoms with the same atomic number but with different numbers of neutrons

5. How do I recognize an isotope? Firstly, the atomic mass weighs the protons and neutrons in the nucleus. So if you add or lose neutrons then the mass will change.