Unit 7: Alpha, Beta & Gamma Radiation

Question 1

Alpha particle

Answer 1

A positively charged particle consisting of two protons and two neutrons. They are highly ionising, but can be stopped by a few centimetres of air.

Question 2

Beta particle

Answer 2

A high speed electron that a nucleus emits when a neutron converts into a proton & an electron. They are ionising but can be stopped by a thin sheet of aluminium.

Question 3

Gamma radiation

Answer 3

Electromagnetic radiation emmited from a nucleus. They have a very high penetrating power & require several centimetres of lead to absorb them

Question 4

Atomic number (proton number)

Answer 4

The number of protons in the nucleus of an atom

Question 5

Mass number (nucleon number)

Answer 5

The number of protons plus neutrons in the nucleus of an atom

Question 6

Isotopes

Answer 6

Atoms of the same element with the same number of protons (atomic number) but different numbers of neutrons (mass number)

Question 7

Ionisation

Answer 7

The process by which ions are formed by gain or loss of electron(s) from an atom

Question 8

Electrons

Answer 8

Negatively charged constituents of an atom, found in different energy levels around the nucleus.

Question 9

Becquerel

Answer 9

The unit of radioactive decay

Question 10

Activity

Answer 10

The rate at which an unstable nucleus decays

Question 11

Radioactive decay

Answer 11

The random process involving unstable nuclei emitting radiation to become more stable

Question 12

Geiger-Muller Tube

Answer 12

A device used to detect ionising radiation

Question 13

Half-Life

Answer 13

The time it takes for the number of unstable nuclei of an isotope in a sample to halve

Question 14

Ionising radiation

Answer 14

Radiation that can cause cell mutations, damage cells & tissues, & lead to cancers