History Of Atomic Structure

Question 0

John Dalton(1808)

Answer 0

He did many chemical experiments and found that COMPOUNDS were different elements combined in specific ratios

Question 1

Democritus(400 B.C.)

Answer 1

Greek philosopher who used the word “atomos”(not to be cut) to describe the smallest piece of matter

Question 2

J.J. Thompson(1897)

Answer 2

Invented the cathode ray tube which created a stream of negatively charged particles that he called “corpuscles” and were later named ELECTRONS

Question 3

Ernest Rutherford(1911)

Answer 3

Gold foil experiment;He concluded that each atom of gold had a small dense, positively charged NUCLEUS surrounded by mostly empty space

Question 4

Niels Bohr(1913)

Answer 4

Determined that the electrons moved in specific energy levels,or SHELLS ,around the nucleus

Question 5

James Chadwick(1932)

Answer 5

Discovered that most atoms contained NEUTRONS as a neutral particles in the nucleus of an atom

Question 6

Cloud Model(1920’s to present)

Answer 6

It states that electrons cannot be located at any exact position but are best represented by a negatively charged CLOUD around the nucleus

Question 7

Dimitri Mendeleev (1869)

Answer 7

Created the first PERIODIC TABLE OF THE ELEMENTS