Nuclear Radiations Revision Packs (P2)

Nuclear Radiations – Revision Packs (P2)

Ionisation:

Atoms contain the same number of electrons (negative charge) as they do protons (positive charge), making them neutral.

Ionisation involves losing or gaining electrons:

-When an atom loses electrons, it becomes positively charged

-When an atom gains electrons, it becomes negatively charged

When ions are formed, chemical reactions can be caused. These reactions can cause damage to strands of DNA, and as such, change the shape of protein molecules in the body. This can have a potentially harmful effect and cause cancer.

Properties of ionising radiations:

Alpha, beta and gamma radiations come from the nucleus of an atom:

Radiation / Ionising? / Penetrating? / Absorbed by?
Alpha (short range of a few cm) / Most ionising / Least penetrating / Absorbed by a sheet of paper or card
Beta (range of about 1m) / Middle / Middle / Absorbed by a few mm of aluminium
Gamma / Least Ionising / Most Penetrating / Absorbed by a few cm of lead

NOTE – while a few cm of lead will normally absorb the gamma radiation, some can pass through several metres of lead or concrete.

Uses of Radioactivity:

Alpha / Beta / Gamma
Smoke alarms use alpha radiation. The radiation ionises the O2 and N2 in the air, creating a small current. When the smoke comes, the air is not as ionised, the current is less and the alarm sounds. / Thickness in a paper-rolling mill uses beta radiation and a detector. The amount of radiation passing through each sheet is looked at, and the pressure on the rollers adjusted accordingly. / In the sterilisation of medical instruments, gamma radiation is used because it kills microbes and bacteria. It is also used as a tracer in pipes to check for blockages and leaks.

The passage of blood around the body and other substances can also be monitored using a gamma OR beta source.

Nuclear Waste:

Radioactive waste can stay radioactive for thousands of years. It should always be stored where it CANNOT leak into underground water supplies or lakes and rivers. While it may not be suitable for making nuclear bombs, it could be used by terrorists to contaminate water supplies or areas of land.

Nuclear Power: Good and Bad:

There are both advantages and disadvantages to using nuclear power stations:

Advantages: / Disadvantages:
-Fossil fuels which are running out are NOT used
-There are NO greenhouse gases given out into the atmosphere, so it doesn’t contribute to global warming / -They have high maintenance and decommissioning costs
-There is always a risk of accidents like that of Chernobyl repeating

Past Papers:

PPQ(1):

PPQ(2):

PPQ(3):

PPQ(4):

PPQ(5):