1. MAIN IDEAS 1.Electrons 2.Cathode Ray 3.Protons 4.Neutrons 5.Nucleus KEY CONCEPTS 1.What are the kinds of subatomic particles? 2.How can you describe the structure of the nuclear atom? IaN pg. 5

2. 2 Electr on Cloud REGIO NS PARTIC LES Neutr on Nucle us Proto n Electr on I. Subatomic Particles A. Protons (+), Electrons (-), Neutrons (0) B. Change to Dalton’s Theory = atoms are divisible!

3. 1. In 1897 JJ Thomson (1856 – 1940) discovered that atoms contain tiny, negatively charged particles called electrons using the Cathode Ray Experiments.

4. Negative ly Charged Beam Positively charge plates

5. Watch what happens when the magnet is placed above and below the electron beam.

6. D.Robert Milikan (1868-1953) 1. U.S. Physicist 2. Experiments quantity of charge a. Thomson’s ratios calculates mass of electron (1916) 3. One unit of negative charge & 1/1840 the mass of a Hydrogen atom Why a Hydrogen atom?

7. 1. 1932 – Eugene Goldstein (1850 – 1930) a. Evidence of positively charged particles using Cathode Ray = Protons b. Mass 1840 X an electron

8. 2. 1932 James Chadwick, English Physicist (1891 -1974) discovers the neutron. a. No Charge b. Mass nearly = to proton How are the subatomic particles arranged?

9. 1. 1911, Ernest Rutherford (1871 -1937) provided evidence that the atom is mostly empty space. He named, nucleus = small dense (+) charged center. a. Gold Foil Experiment – Alpha particles passing through & deflected by gold foil

10. Dalton’s Model “Solid Sphere” Thomson’s Model “Plum Pudding” “Solar System” Rutherford’ s Model NUCLEAR ATOM – Protons & Nuetrons in the nucleus. Electrons take up most of the volume

11. ORAN GE CARD GREEN CARD # NOTES = N TEXTBOOK = T w/ PAGE # MISSED GREEN CARD #’s % CORREC T 15 = N3 Card Sort Activity Top ½ IaN pg. 4 INFERENCEREFERENCE