Chem 1.2 Developing the Atomic Theory

Question 1

Democritus

Answer 1

• said matter can be cut into smaller and smaller pieces until a tiny particle can’t be cut anymore
• called the particle ATOM

Question 2

John Dalton

Answer 2

• Matter consists of small particles called atoms
• Each element is made up of its own type of atom
• Atoms of different elements have different properties
• Atoms combine in whole number ratios
• Atoms cannot be destroyed or anything in a chemical change

Question 3

J.J Thomson

Answer 3

• Used Cathode Ray Tube to find electrons
• The overall charge on the atom is neutral
• Used the Raisin Bun Model

Question 4

Ernest Rutherford

Answer 4

• Discovered the nucleus
• Atom has positively charged nucleus
• Some of this space has electrons

Question 5

James Chadwick

Answer 5

• Said there are neutrons in the nucleus = no charge
• Isotopes were there

Question 6

Bohr

Answer 6

• Found electron energy levels
• Found shells that SURROUND nucleus
• Developed the study of Line Spectrum