Scientists

Question 1

Democritus

Answer 1

Named the atom

Matter is indivisible

Question 2

Dalton

Answer 2

5 Principles
	All matter is made of atoms
	Atoms of an element are identical
	Each element has different atoms
	Atoms of different elements combine in constant ratios to form compounds
	Atoms are rearranged in reactions

Question 3

Thomson

Answer 3

Atoms are made of smaller particles
Cathode Ray experiment
Discovered the electron
Plum Pudding Model

Question 4

Rutherford

Answer 4

Atoms are mostly empty space
Gold foil experiment
Discovered the nucleus

Question 5

Lavoiser

Answer 5

Law of Conservation of Mass

Matter can’t be created/destroyed

Question 6

Proust

Answer 6

Law of Definite Proportions

Question 7

Berthollet

Answer 7

Law of Multiple Proportions

Question 8

Milkan

Answer 8

Oil Drop Experiment

Question 9

Chadwick

Answer 9

Proved the existence of the neutron

Question 10

Bohr

Answer 10

Planetary Model of the atom

Question 11

Mendeleev

Answer 11

First periodic table (arranged by mass)

Question 12

Moseley

Answer 12

Modern periodic table (atomic number)

Question 13

Planck

Answer 13

Energy is quantized

Question 14

Heisenberg

Answer 14

Uncertainty Principle:

It is impossible to determine the exact location of an electron

Question 15

Schrodinger

Answer 15

Mathematical Equations to predict & calculate atomic energy as electrons move

Question 16

Hund

Answer 16

Hund’s Rule:

Within a sublevel, place one electron per orbital before pairing them

Question 17

Aufbau

Answer 17

Aufbau Principle:

Electrons fill the lowest energy orbitals first

Question 18

Pauli

Answer 18

Pauli Exclusion Principle:

Each orbital can hold 2 electrons with opposite spins

Question 19

Newlands

Answer 19

Law of Octaves