Topic 20: Nuclear Physics

Question 1

Mass defect

Answer 1

The difference between the total mass of individual, free nucleons and the mass of the nucleus.

Question 2

Nuclear binding energy

Answer 2

The minimum energy required to separate the nucleons in a nucleus to infinity.

Question 3

Nuclear Fusion

Answer 3

Combining two or more light nuclei under very high temperatures to form a single, more massive nucleus.

Question 4

Nuclear fission

Answer 4

Splitting of a single heavy nucleus when bombarded by nucleons to form two or more light nuclei of approximately the same mass with neutrons emitted.

Question 5

Random decay

Answer 5

It is impossible to predict if an unstable nucleus will decay at any point of time, only the probability of decay after a period of time is known.

Question 6

Spontaneous decay

Answer 6

Probability of decay is unaffected by external conditions such as temperature, pressure or chemical composition.

Question 7

Decay constant

Answer 7

Probability per unit time of the decay of a nucleus.

Question 8

Half life

Answer 8

The time taken for the number of undecayed nuclei to be reduced to half of its original number.