chem

group 1

alkali metals

group 2

alkaline earth metals

middle

transition metals

bottom 1

Lanthanides

botton 2

actinides

stair (B-Po)

metalloid

under stair

other metal

over stair

non metals

group 17

Halogens

group 18

noble gases

Proposed "Atomic Theory" used breaking shells to prove that everything was made of little balls of stuff

democritis

Thought that mass cannot be created or destroyed, she also found 33 elements

Antoine Lavoisier

Proposed there are different kinds of atoms, came up with partical pressure

Jhon Dalton

Proved that an atom can be divided and can actually have stuff inside of them using the plum pudding theory, used a cathode

JJ Thomson

he found the nucleus

Ernest Rutherford

Suggested that there are negative and positive electrons + a positive nucleus (planetary model)

Niels Bohr

Said electrons are too fast to see (cloud model)

Erwin Shrodinger

Discovered the neutron

James Chadwick