Science Atomic Theory Flashcards
What date is Democritus
440 BCE
When was JJ Thomson
1897
When was Chadwick
1932
When was Dalton
Late 1700’s but he proposed the theory in 1803
When was Rutherford
1909
When was Bohr
1913
Who pounded up materials in his pestle and mortar and called them “ATOMOS”
Democritus
first to have the idea of “an atom” being the smallest particle of all matter
Democritus
Who was a Greek philosopher
Democritus
translates the Greek word “atomos” into atoms
Dalton
Who proposed the atomic theory
Dalton
stated that all substances are made of atoms
Dalton
stated that atoms cannot be divided, created or destroyed
Dalton
Who stated that atoms of the same element are exactly alike and atoms of different elements are different
Dalton
Who used the plum pudding model
JJ THOMSON
thought Dalton’s theory wasn’t quite right
Thomson
Who discovered the electron
Thomson
Who used a cathode ray tube
Thomson
Who wanted to test Thomson’s theory
Rutherford
Who used the gold foil experiment
Rutherford
Who discovered the nucleus
Rutherford
found that the nucleus is a small dense, positively charged center of an atom
Rutherford
proposed that electrons move around in a certain path or energy levels
Bohr
suggested that there were a certain number of electrons that the energy level can hold
Bohr
his model explained that the electrons orbit the nucleus just like how the planets orbit the sun
Bohr
believed that the nucleus was too heavy for just the protons alone
Chadwick
believed that there were particles in the nucleus with no charge
Chadwick
Who discovered the neutron
Chadwick
