IGCSE Physics : Topic 5 Atomic Physics

Topic 5.1- Radioactivity

Background radiation-the small amount of radiation around us all the time because of radioactive materials in the environment. It mainly comes from natural sources such as soil, rocks, air, building materials, food and drink – and even space.
Radioactivity detection- Geiger-Muller tube (G.M. tube)
Radioactive Decay

Alpha decay- two proton and two neutron left

Beta decay- Gain proton

Gamma emission- No change of proton and nucleon number

Half life
time taken for half the nuclei present in any given sample to decay. Some nuclei are more stable than others.

Safety Precaution
-radioactive stuff is stored in a lead container, in a locked cabinet
-picked up with tongs, not your feet
-kept away from the body, not pointed at people

-left out of its container for as short a time as possible

Share on Google Plus


  1. I found this note very informative thanks for sharing this!