quiz Flashcards
(6 cards)
1
Q
Democritus
A
a Greek philosopher, was the first to think about the atoms existence,believed that matter was composed of tiny invisible particles called atoms, he had no experimental evidence to support his thoughts
2
Q
john Dalton
A
a meteorologist, had experimental evidence to support his theory,
3
Q
Dalton had 4 major points to his theory
A
- all elements are composed of invisible particles called atoms 2. atoms of the same element are identical. the atoms of any one element are different from those of another. 3. atoms of different elements mix or combine in whole number ratios. 4. chemical reactions occur when atoms separate, join, or rearrange. in a chemical reaction, atoms of one element never change into another.
4
Q
j.j. Thompson
A
in the tube was an inert gas and two plates, a positive and a negative, the particles in the gas were attracted to the positive plate, discovered the electron
5
Q
Ernest Rutherford
A
used the gold foil experiment to discover nucleus
6
Q
protons and neutrons
A
Eugene goldstein discovered the proton, James Chadwick discovered the neutron