atomic theory Flashcards
history of the atomic theory (people, experiments, laws, etc.)
1
Q
(1st) Democritus discovered…
A
first proposed all matter was composed of atoms (atomos), used grapes, but more philosophy than science
2
Q
3 laws that led to first atomic theory?
A
- law of definite proportion
- law of conservation of mass
- law of multiple proportions
3
Q
law of definite proportion
A
any sample of a compound always has the same composition (chemically)
4
Q
law of conservation of mass
A
matter cannot be created or destroyed only transformed
5
Q
law of multiple proportions
A
different compounds have different mass porportions
6
Q
(2nd) John Dalton discovered…
A
- all matter made of indivisible, identical atoms, atoms of diff. atoms are diff., had the marble model!
7
Q
JJ Thomson discovered…
A
he worked with a cathode ray tube, discovered electrons, atoms not indivisible, plum pudding model!
8
Q
Ernest Rutherford discovered…
A
worked with gold foil (alpha particles) experiment discovered the nucleus, and that the atom is mostly empty space
