Atomic Theory

Label the changes from 1 (earliest) to 5 (latest)

a

b

c

d

e

3

5

1

2

4

Because we cannot see atoms, we use ​ (a)   to teach and learn about atoms.

The atomic theory has ​ (b)   over time as new technologies become available

• models
• changed
• sticks
• ice
• videos

​ Atomic theory scientists

• Discovered the atomic nucleus.

• Niels Bohr

• All matter is made of atoms.

• Ernest Rutherford

• Discovered the negative electron.

• James Chadwick

• Discovered the neutron.

• John Dalton

• Proposed the planetary model of the atom.

• J.J Thompson

Atomic theory timeline

Order the scientists contribution to the atomic theory in order from earliest (1) to latest (5)

• John Dalton

• JJ Thompson

• Ernest Rutherford

• James Chadwick

• Neils Bohr

What was John Dalton's contribution to the atomic theory?

• John Dalton discovered the electron and its charge.
• John Dalton proposed that all atoms are nonexistent.

• John Dalton introduced the concept of radioactivity in atomic theory.
• John Dalton contributed to the atomic theory by proposing that matter is composed of indivisible atoms .

What was JJ Thompson's contribution to the atomic theory?

• JJ Thompson discovered the neutron and proposed the planetary model.
• JJ Thompson was the first to identify the nucleus of an atom.
• JJ Thompson contributed to atomic theory by formulating the quantum model.
• JJ Thompson contributed to atomic theory by discovering the electron and proposing the plum pudding model.

The discovery of the ​ (a)   was in 1897, when scientist JJ ​ (b)   used a ​ (c)   .

• electron
• Thompson
• cathode ray tube
• proton
• Rutherford
• microscope

Ernest __________ was the scientist who discovered the nucleus.

Which experiment was Ernest Rutherford known for?

• Oil drop experiment
• Gold foil experiment
• Plum pudding model
• Cathode ray experiment

What was James Chadwick's contribution to the atomic theory?

• James Chadwick discovered the proton.
• James Chadwick proposed the theory of relativity.
• James Chadwick discovered that the neutron has a neutral charge.

• James Chadwick invented the electron.