science- history of the atom

Question 1

Atomic Theory

Answer 1

500 BC
Democritus
Everything is made of particles that can’t be broken down

Question 2

Solid spheres

Answer 2

1800’s
John Dalton
The tiny particles are solid spheres, different spheres make different elements

Question 3

plum pudding model

Answer 3

1897
J. J Thompson
disproved the solid sphere theory, suggests lots of negative parties float in a general ball of positive charge

Question 4

Nuclear Model

Answer 4

1909
Ernest Rutherford
shot positive alpha particles at thin sheets of Gold, disproving that negative particles are evenly distributed in the atom.
suggested a positive nucleus was surrounded by a negative ‘cloud’

Question 5

Electron shells

Answer 5

1913
Niels Bohr
electrons are held in shells + orbit the nucleus like the sun.

Question 6

Protons

Answer 6

Ernest Rutherford
The nucleus is made of multiple positive particles - protons

Question 7

Neutrons

Answer 7

James Chadwick
The nucleus also contains neutral particles - neutrons