History and Atomic Structure

Question 1

1800, John Dalton

Answer 1

atoms are tiny, hard, undividable structures, rearrange in chemical reactions, each element has its own mass of atoms

Question 1

first to have ideas on atoms and particles

Answer 1

ancient greeks

Question 2

early 1800s, J.J. Thompson

Answer 2

discovery of the electron = tiny negative particle, plum pudding model

Question 3

plum pudding model

Answer 3

negatively charged particle embedded in a cloud of positive charge

Question 4

late 1800s, Geiger and Marsden

Answer 4

disproved plum pudding model via alpha scattering experiment proving the nucleus of protons and electrons orbit the nucleus

Question 5

alpha scattering experiment

Answer 5

alpha, positive particle fired at thin gold foil, repelled back at source showing there must be positive charge concentrated

Question 6

1914, Niels Bohr

Answer 6

electrons orbit at set distances and give out energy when going from high to low energy

Question 7

1932, James Chadwick

Answer 7

neutrons proved