1. Atomic Theory Math Isotopes, Ions, and Average Atomic Mass

2. Parts of atom as of now NameLocationActual Mass (kg) Relative Mass (amu) Actual Charge (C) Relative Charge Proton,p + nucleus1.67*10 -28 1+1.68*10 -19 +1 Neutron, n 0 nucleus1.67*10 -28 100 Electron, e - Outside the nucleus in energy levels 9.1*10 -31 0-1.68*10 -19

3. Ions – electrically charged particles Positive ions – lose electrons +1 lose one electron +2 lose two electrons +3 lose three electrons Negative ions – gain electrons -1 gain one electron -2 gain two electrons -3 gain three electrons

4. Atomic number – number of protons, Z, id’s the element Mass Number – number of protons plus neutrons, A Why is electron NOT part of mass number Isotopes – same element different mass same atomic number different mass number same number of protons different number of neutrons same Z different A

5. Isotopes chart (Red text was originally blank) IsotopeAtomic Number Mass Number p+p+ n0n0 e-e- C-12612666 C-13613676 C-14614686 1H1H11101 2H2H12111 3H3H13121 16 O816888 Let’s mix it up now Mg-261226121412 Ne-20102010 U-232922329214092

6. Average Atomic Mass Weighted average – the isotope most in abundance skews the average Mass number *abundance + Mass number *abundance -------------------------------------------------------------------------- = Average atomic mass total abundance