Topic 4 atomic structure

Question 1

alpha particles

Answer 1

alpha particles emitted from a nucleus the particle has 2 neutrons and protons. they don’t penetrate very far and last a few minutes in the air due to their high ionisation. used in smoke detectors.

Question 2

beta particles

Answer 2

beta particles are high-speed electrons. Have no mass and a charge of -1. Moderate ionising they have a range of a few meters in the air and is absorbed by a sheet of aluminium. For every beta particle emitted a neutron in a nucleus has turned into a proton

Question 3

Gamma rays

Answer 3

They are electromagnetic waves. They penetrate far into materials and far in the air. It has weak ionising effect so it is absorbed by thick sheets of lead or metres of concrete

Question 4

Replacing the plum pudding model with the nuclear model

Answer 4

Rutherford fired alpha particles at a thin layer of gold they found that most of the particles pass through and some were deflected into other directions and few bounced straight back so the plum pudding couldn’t be right