Nuclear(u3b)

• Radioactivity is all around us. We are constantly being bombarded by particles and rays, this is often described as background radiation.
• Alpha Particles, (α):

  -They are made up of a Helium nuclei, He2+

  -Alpha particles have a positive charge so they are attracted (deflected) to the negative side.

  -Alpha particles are the biggest and they can be stopped by a thin piece of paper.

  
• Beta Particles,β:

  -very high energy (fast moving) electron.

  -Beta particles are negatively charged so they are attracted (deflected) to the positive side.

  -The smaller beta particles can travel a few metres through the air but will be stopped by a few millimetres of aluminium.

  
• Gamma Waves, (γ):

  -These are not particles. They are a form of electromagnetic radiation, “waves” and they come from the nucleus.

  -Gamma rays are not charged so pass through unaffected.

  -Gamma rays have no mass and charge and can travel long distances. They are only stopped by thick lead and even thicker concrete.

  
• When the three different types of radiation are passed through an electric field they are affected in different ways:

  
• The radioactive emissions also have different penetrating powers: