history of the atom

Question 1

460BC

Answer 1

greek philosopher
inspired by sand forming pebbles- must eventually be able to reach the smallest part

Question 2

1803

Answer 2

round sphere
can’t be broken-down into anything simpler
during chemical reactions atoms rearrange to make different substances

Question 3

1897- JJ Thompson

Answer 3

plum pudding model
discovered the electron
atoms overall neutral
sphere of positive charge
electron dotted around inside

Question 4

1911- Rutherford

Answer 4

• tested plum pudding model
• aimed beams of positively charged alpha particles at very thin gold foil
• particles should’ve passed straight through however many changed direction
• led to nuclear model –> central positive nucleus containing protons with electrons orbiting

Question 5

1913

Answer 5

extended rutherfords work
electrons orbit in fixed postions around the nucleus
electrons could jump from one level to next

Question 6

1932

Answer 6

found out about neutons