L9 | ATOMIC STRUCTURES | Atomic models

Question 1

Order the scientist from oldest to newest.

Answer 1

1. Democritus
2. Dalton
3. Thomson
4. Rutherford
5. Bohr
6. Chadwick

Question 2

What are atoms?

Answer 2

The building blocks of all matter. Atoms are the basis of all the structures and organisms in the universe.

Question 3

What is an atom made up of?

Answer 3

A positively charged nucleus in the center is surrounded by negatively charged electrons.

Question 4

How did John Dalton view an atom?

Answer 4

As tiny, microscopic balls.

Question 5

What was Thomson’s model of the atom?

Answer 5

He thought that the atom is made up of negative electrons that float in a “soup” of positive charge, much like plums in a pudding or raisins in a fruit cake

Question 6

What was Thomson’s model of the atom called?

Answer 6

Plum Pudding Model

Question 7

What was Rutherford’s model of the atom?

Answer 7

Described the atom as a tiny, dense, positively charged core called a nucleus surrounded by lighter, negatively charged electrons.

Question 8

What is Rutherford’s model of the atom?

Answer 8

‘Planetary model’ of the atom.

Question 9

What was the problem with Rutherford’s model?

Answer 9

That it could not explain how atoms only emit light at certain wavelengths or frequencies.

Question 10

What was Bohr’s model of the atom?

Answer 10

He thought that the electrons could only orbit the nucleus in certain special orbits at different energy levels around the nucleus.

Question 11

What did Chadwick’s discovery?

Answer 11

He thought another kind of particle must be present in the nucleus along with the proton. He discovered the neutron and measured its mass.