History Of The Atom

Question 1

John Dalton

Answer 1

(Early 1800’s)
-English School teacher
-Said atoms were the smallest particle of matter
-Atoms of the same element had the same mass and properties
-COULD NOT EXPLAIN BONDING
-Billiard ball model

Question 2

Sir William Crooks

Answer 2

(1890’s)
-Cathode ray tube experiments
-Theorized the existence of electrons

Question 3

JJ Thompson

Answer 3

-1897 refined the cathode ray tube -Proved electrons existed
-1903 proves protons existed
-Atoms made of protons and electrons
-Protons gave mass and electrons held it together
-plum pudding model

Question 4

Becquerel

Answer 4

(1896)
Accidentally discovered radio activity

Question 5

Rutherford

Answer 5

(1911)
-Protons are in middle of atom
-Electrons rotated around the centre
-Most mass in Nucelus
-Planetary model

Question 6

James Chadwick

Answer 6

(1932)
-Neutron discovered
-Neutron was nucleus and was mass of atom
-modified planetary model

Question 7

Dmitri Mendeleev

Answer 7

-Russian
-organized by chemical properties and increasing atomic mass
-Left blank spots
-“Father of the periodic table”