Chapter 7.2

Question 1

Who discovered that atoms were divisible and made up of smaller particles (electrons)?

Answer 1

Joseph John Thomson

Question 2

Whys is it called the Thomson plum pudding model?

Answer 2

He compared a plum pudding to a positively charged material, where the ‘cake’ is the positively charged material and the ‘fruit’ are the electrons.

Question 3

How did Ernest Rutherford’s ‘gold foil’ experiment work?

Answer 3

Rutherford set up a very thin layer of glod and fired a stream of radioactive particles at it. Detectors to record the radioactive alpha particles were
set up around the gold foil to identify whether particles
had gone through or deflected.

Question 4

What were the ‘gold foil’ experiment’s results?

Answer 4

Most particles passed through but some fast-moving high energy aphpa particles bounced back.

Question 5

What was Rutherford’s conclusion?

Answer 5

Atoms must contain a lot of space, of which
some part contains a relatively large amount of positive
charge – called the nucleus.