Where do elements come from?“Every atom in your body came from a star that exploded. And, the atoms in your left hand probably came from a different star than your right hand. It really is the most poetic thing I know about physics: You are all stardust.”

- Lawrence Krauss

http://www.teachersdomain.org/resource/ess05.sci.ess.eiu.fusion/

What’s inside an atom?

• Greeks: atom• Dalton’s Atomic Theory (1766-1844)

1)2)3)4)5)

Pair up!

Complete the Atomic Pudding Worksheet (Skip questions 5 and 6)

Subatomic particle #1: Electron

• J.J. Thomson’s cathode ray (1897)

http://www.youtube.com/watch?v=O9Goyscbazk

Electron:

Subatomic particle #2: Proton

• Rutherford’s gold foil experiment (1911)

Expected

Actual Nucleus:

Subatomic particle #3: Neutron

Isotope

Atomic number

Mass number

Models and theories can change over time

1803 1897 1911 1913 1918

Protons identify an element, electrons tell you what it can do

• Protons

• Electrons