Name four natural sources of background radiation.

Why is radon gas a significant source of background radiation?

Give two examples of man-made (artificial) sources of background radiation.

Define corrected count rate.

How can the background radiation count be found from a graph of count rate against distance from a source?

Cosmic rays entering the Earth's atmosphere collide with molecules in the air, producing ______ radiation.

True or False? Nuclear power stations are the largest contributor to background radiation.

List the four ways ionising radiation can damage human cells and tissue at high doses.

Why might a doctor recommend radiotherapy for a patient despite the risks of radiation?

How can ionising radiation lead to a mutation?

What effect can acute radiation exposure have on the immune system?

How should a radioactive source be handled to minimise risk?

Why is radioactive waste with a long half-life buried deep underground?

Radioactive sources should be stored in ______ boxes to shield people from radiation.

True or False? Gloves and safety glasses are always required, in addition to tongs, when handling radioactive sources.

Define count rate.

Which two detectors are used to detect alpha particles?

How can an alpha particle's track be identified in a cloud chamber?

Describe how a spark counter detects alpha radiation.

Which detector is most commonly used to detect beta particles and gamma radiation?

How does the count rate detected change as distance from a radioactive source increases?

A cloud chamber contains a thin film of ______ vapour, cooled using dry ice, which condenses to form visible tracks.

True or False? A cloud chamber is set up with a magnetic field at right angles to the chamber.

Define nuclear fission.

Define nuclear fusion.

Define a chain reaction.

Besides two smaller (daughter) nuclei, what else is produced when a large nucleus undergoes fission?

What is the purpose of control rods in a nuclear reactor?

What is the purpose of the moderator in a nuclear reactor?

In both fission and fusion, the mass of the products is slightly less than the mass of the starting nuclei because the missing mass has been converted into ______.

True or False? Nuclear fusion requires extremely high temperatures to occur.

Define half-life.

How is carbon-14 formed in the atmosphere?

Why does the proportion of carbon-14 in a living organism stay constant?

What is the approximate half-life of carbon-14?

Over what approximate age range is carbon dating considered reliable?

Why is carbon dating unreliable for samples older than 40 000 years?

Each time one half-life passes, the activity of a radioactive sample falls to ______ of its previous value.

True or False? The half-life of an isotope decreases as a sample gets older.

Define radioactive decay.

Define random, in the context of radioactive decay.

Why is carbon-14 unstable while carbon-12 is stable?

How do the mass number and atomic number change during alpha decay?

How do the mass number and atomic number change during beta decay?

How do the mass number and atomic number change during gamma decay?

During alpha decay, the atomic number decreases by ______ and the mass number decreases by ______.

True or False? The atomic (proton) number of a nucleus is determined only by the number of protons it contains.

Define radioactive decay.

Define gamma radiation.

What does it mean for radioactive decay to be a random process?

What does it mean for radioactive decay to be a spontaneous process?

State the nature and charge of an alpha particle.

What is a beta particle, and how is it produced in the nucleus?

Describe the trend in range, penetrating power and ionising power down the table from alpha to beta to gamma radiation.

Alpha radiation is stopped by paper; beta radiation is stopped by a few mm of ______; gamma radiation is only partially stopped by a few mm of thick lead.

Why is gamma radiation not deflected by electric or magnetic fields, while alpha and beta particles are?

True or False? Beta particles are deflected towards the negative plate in an electric field.

Why are alpha particles used in smoke detectors rather than beta or gamma?

Why are beta particles (not alpha or gamma) used to monitor the thickness of a material?

Why are gamma rays used in radiotherapy to treat tumours?

Define a tracer, in the context of medical uses of radiation.

Why is gamma radiation used to sterilise medical equipment?

Give two uses of radiation besides smoke detectors, thickness gauging, cancer treatment and sterilising equipment.

Beta particles are used to measure material thickness because they are ______ absorbed by the material, unlike alpha (fully absorbed) or gamma (mostly passes through).

True or False? During radiotherapy, the gamma beams are moved around the patient to minimise damage to healthy tissue.