P7- discovery of the nucleus

Question 1

What is the plum pudding model of the atom?

Answer 1

A sphere of positively
charged material with negatively charge particles (electrons) spread through it.

Question 2

Describe the gold foil experiment

Answer 2

A thin sheet of gold was used to scatter a beam of alpha particles. Particles were
strongly reflected/diverted when they came close to the nucleus of the gold particles

Question 3

How did this lead to the plum pudding model of the atom being rejected?

Answer 3

It showed that a small part of each atom was positively charged as most alpha
particles passed through without deflection.

Question 4

What is Bohr’s model of the atom?

Answer 4

that the electrons in an atom orbit the nucleus at specific distances and
energy levels.

Question 5

How can we change the distance of an electron from the nucleus?

Answer 5

We change the distance of an electron from the nucleus by the electron absorbing or
emitting electromagnetic radiation.