Radiation (2)

Beryllium-9 is a stable isotope of beryllium. 

      State the meaning of the term stable. 

• Has a long half-life

• Undertakes radioative decay

• Does not emit ionising radiation

• Emits ionising radiation

Alpha, beta and gamma are types of ionising radiation.

 Which of the following is NOT a description of how gamma radiation is different from alpha radiation.

• Alpha is a helium nucleus

• Alpha has a mass

• Gamma penetrates further

• Gamma travels slower

Ionising radiations are emitted by unstable nuclei.

Some unstable nuclei decay by emitting β⁻ radiation.

Describe the process of B- emission

Answer explanation

Iodine-131 is a radioactive isotope with a half-life of 8 days.

The activity of a sample of iodine-131 is 480 Bq.

Calculate the activity of the sample after 16 days.

• 80 Bq

• 120 Bq

• 240 Bq

• 480 Bq

Which of these describes half-life?

• the time it takes for half of the undecayed nuclei to decay

• the time it takes for all of the undecayed nuclei to decay

• half the time it takes for all of the undecayed nuclei to decay

• half the time it takes for half of the undecayed nuclei to decay

What type of radiation is used for sterilisation of medical equipment?

• alpha

• beta

• gamma

• Xray

What type of radiation is used in household fire (smoke) alarms?

• Alpha

• Beta

• Gamma

• Xray

What type of radiation is used in gauging thickness of cardboard?

• Alpha

• Beta

• Gamma

• Xray

What type of radiation is used in irradiating food?

• Alpha

• Beta

• Gamma

• Xray

Radioactivity is used in PET scanners in hospitals.

Describe one use of PET scanners in hospitals.

Answer explanation