1. History of Atomic Model Democritus: atoms – tiny particles of matter Socrates, Plato, and Aristotle: earth, wind, fire and water John Dalton: Atomic Theory Berzelius: name and symbol

2. J.J. Thomson: electron (Cathode Rays), small, e -, move rapidly. Rutherford: nucleus (Gold Foil), solid, +, small Neils Bohr: Solar system model, e-: planets, nucleus: sun,

3. Moseley: p+, large, +, held in nucleus C. Chadwick: n 0, large, neutral, mass of a neutron is 1.675 x 10 -27 kg Joliet: 1 st synthetic element (Tc – 99)

4. Modern chart IUPAC: Regulates the Periodic chart changes Robert Millikan: mass of an electron is 9.109 x 10 –31 kg (oil-drop experiment)

5. Experiments Cathode Ray

6. Experiment Gold Foil

7. PARTS OF THE ATOM NUCLEUS PROTON(S) + CHARGE, 1 amu, NEUTRON(S) 0 CHARGE, 1 amu ENERGY LEVELS ELECTRON(S) - CHARGE, 0 amu

8. Parts of the atom Nucleus Protons &neutrons Energy levels Electrons

9. Atomic Symbol Atomic symbol 15 protons + neutrons N Symbol 7 protons ( also #of electrons ) Atomic Diagram

10. ATOMIC DIAGRAM BASIC DIAGRAM OF LOCATION OF PARTICLES Nucleus p n Energy levels e

11. Atomic Diagram p + 7 n 0 8 p + 7 e - 7 2e - 5e - n 0 8

12. Isotopes Differ in the # of neutrons Hydrogen1 protium (most common, natural) p + 1 e - 1 n 0 0

13. Hydrogen 2 deuterium (naturally occurring) p + 1 e - 1 n 0 1 Hydrogen-2

14. Hydrogen - 3 Hydrogen 3 tritium (man-made 1930’s) p + 1 e - 1 n 0 2 Uses in heavy water

15. Terms Avogadro: molecular volume theory (mol) Avogadro’s # 6.022x10²³ Atomic # number of protons Atomic Mass protons + neutrons Molar Mass mass of 1.00 moles of an element in grams

16. Mole Math Equivalent statements 1.00mole = one Molar Mass 1.00mole = 6.022x10²³ 1.00 mole = 22.4 Liters of a gas at STP Therefore they equal each other.

17. Math set - up How many grams in 2.35 moles of zinc? molar mass 2.35 mol Zn 65g ÷ 1.00 mol × = 152.75 sig fig = 153g of Zn