RADIOACTIVE SUBSTANCES

Radioactive Substances – Deflecting Radiation & Background Radiation

Radioactive Substances – Deflecting Radiation & Background Radiation

Deflecting Radiation

Physics GCSE Science Revision - Radioactive SubstancesIn order to understand how radiation can be deflected it’s important to know the charge carried by each form of radiation:

  • – alpha particles have a positive charge
  • – beta particles have a negative charge
  • – gamma radiation has a neutral charge

This means that alpha and beta particles can be deflected using an electrical field. However, gamma radiation cannot:

  • – alpha particles are deflected by a positively charged plate and attracted towards a negatively charged plate
  • – beta particles are deflected by a negatively charged plate and attracted towards a positively charged plate

Magnetic fields can also be used to deflect alpha and beta particles. However, again, gamma radiation is not affected.

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Atoms and radiation

Background radiation

We’re surrounded by background radiation. Some of it’s given off by natural sources while some of it is given off by artificial sources.

Physics GCSE Science Revision - Radioactive SubstancesNatural sources include:

  • Rocks and soils: radioactive rocks emit radioactive radon gas.
  • Living organisms: radioactive materials are absorbed by plants and enter the food chain.
  • Cosmic rays: radiation in space can come down into Earth.

Natural sources are how most people come into contact with radiation, with radon gas from the ground being the largest source.

Artificial sources include:

  • Radioactive waste: this is the waste product of nuclear power stations.
  • Radioactive fallout: this is produced from nuclear weapons testing
  • X-rays: used for medical purposes and in airports.

For most people, about 15% of their background radiation comes from artificial sources and most is due to medical X-rays.

It’s not possible for human senses to detect radiation. This is why we use specifically designed equipment.