History Flashcards
1
Q
Democritus
A
All matter can be divided into smaller pieces until invisible particle is reached (atom)
2
Q
Aristotle
A
- Rejected the atom theory, said all matter is made up from the earth, water, air & fire
- His theory was accepted for about 2000 years
3
Q
John Dalton
A
- Revived Democritus theory of invisible atom
-all matter was comprised of indivisible and indestructible atoms with distinct masses and properties - Billiard Ball Model
- couldn’t explain why objects attract/repel
- helped explain many properties of matter
4
Q
J.J Thompson
A
- Father of the Electron
- Plum pudding model(mostly positive with negative embedded)
5
Q
Ernest Rutherford
A
the atom is mostly empty space, with nearly all of its mass concentrated in a tiny central nucleus
6
Q
James Chadwick
A
proved the existance of neutrons
7
Q
Niels Bohr
A
a model of the atom in which the electron was able to occupy only certain orbits around the nucleus
8
Q
Democritus Year
A
400 BCE
9
Q
Aristotle Year
A
450 BCE
10
Q
John Dalton Year
A
1807
11
Q
JJ Thompson Year
A
1897
11
Q
Ernest Rutherford Year
A
1909
12
Q
James Chadwick Year
A
1932
12
Q
Neils Bohr Year
A
1913
