Background radiation (T7)

Question 1

When the Earth was formed 4.5 billion years ago it contained many radioactive isotopes. Some decayed quickly but others are still producing radiation.

One form of uranium is a radioactive element that decays very slowly. Describe this..

Answer 1

Two of this form of uraniums decay products are the radioactive gases radon and thoron.

Radon-222 is a highly radioactive gas produced by the decay of radium-226.

Thoron, or radium-220 is an isotope of radium formed by the decay of a radioactive isotope of thorium (thorium-232).

Question 2

Describe natural background radiation from space..

Answer 2

Violent nuclear reactions in stars and exploding stars called supernovae produce very energetic particles and cosmic rays that continuously bombard the Earth.

Lower energy cosmic rays are given out by the sun.

Our atmosphere gives us fairly good protection from cosmic rays.

Question 3

Describe internal radiation..

Answer 3

The atoms in our bodies were formed in the violent reactions that took place in stars created at the beginning of the universe.

Some of these atoms are radioactive so we carry our own personal source of radiation around with us.

Also as we breathe we take in small amounts of the isotope carbon-14.

Question 4

Describe artificial radiation..

Answer 4

Generating electricity in nuclear power stations has been responsible for the leaking of radioactive material into the environment.

Testing nuclear weapons in the atmosphere has also increased the amount of radioactive isotopes on the Earth.