Chapter 3 - Isotopes

Question 1

Democritus

Answer 1

Came up with the idea of an atom (no experimental evidence).

Question 2

Aristotle

Answer 2

Did not believe in atoms; his idea was accepted for nearly 2,000 years.

Question 3

Dalton

Answer 3

First to complete an attempt to describe all matter in terms of atoms and their properties; based his theory on the law of conservation of mass the law of constant composition.

Question 4

Thomson

Answer 4

Plum-Pudding experiment: conducted experiments with cathode ray tubes to show that all atoms contain tiny, negatively charged subatomic particles or electrons.

Question 5

Rutherford

Answer 5

Nuclear model of an atom: Conducted a gold foil experiment with alpha particles showed that the atom is mostly empty space with a tiny, dense, positively charged nucleus.

Question 6

Bohr

Answer 6

Planetary model: Proposed that electrons revolved around a positively charged nucleus.

Question 7

Schrodinger

Answer 7

Stated that electrons do not move in a set path but in waves.

Question 8

Chadwick

Answer 8

Discovered neutrons by placing a piece of beryllium in a vacuum chamber with some polonium.