Science 5 Section 1

Question 0

What did Thomson believe/do?

Answer 0

• His theory of atomic structure led to the “plum-pudding” model
• He conducted the cathode-ray tube experiment
• There are small, negatively charged particles inside an atom

Question 1

What did Democritus believe/ do?

Answer 1

• Atoms are small, hard particles
• Atoms are “uncuttable”
• Atoms constantly move

Question 2

What did dalton believe/do?

Answer 2

• Elements combine in specific proportions
• Atoms of different elements are different
• All substances are made of atoms
• He conducted experiments in combining elements
• Atoms of the same element are exactly alike

Question 3

What did Bohr believe/do?

Answer 3

• Electrons travel in definite paths

- Electrons jump between levels from path to path

Question 4

What did Rutherford believe/do?

Answer 4

• There is a small, dense, positively charges nucleus
• Most of an atom’s mass is in the nucleus
• Conducted the gold foil experiment
• Atoms contain mostly empty space
• Electrons move in empty space in the atom

Question 5

What do S&H believe/ do?

Answer 5

• Electron path can’t be predicted

- Electrons are found in electric clouds, not paths

Question 6

What year was each scientist helpful?

Answer 6

Democritus- 440BC
Dalton- 1803
Thomson- 1897
Rutherford- 1911
Bohr- 1913
S&H- 20th century