Lesson 1: Why study radioactivity?
Introduction
In this lesson we introduce some of the uses of radioactivity and also some of the ways that it can be harmful. We'll see how nuclear radiation is similar to other forms of radiation and also important ways that it differs.
Animation of the radiation warning sign.Uses of nuclear radiation
Nuclear radiation is used in areas as diverse as medicine and engineering, for example: diagnosing and treating disease, finding cracks in concrete structures, monitoring the flow of rivers, measuring the thickness of paper and kitchen foil, sterilising delicate medical equipment, finding the age of ancient remains and preserving food.
Simple activity about the uses of radioactivity. You have to match the picture to the description.The ways nuclear radiation can be harmful
Nuclear radiation can damage our cells causing burns, sickness, diarrhea and vomitting, infertility and sometimes death. Small doses can damage our DNA which can lead to cancer when we're older.
Simple activity about the dangers of radioactivity. You have to match the picture to the description.What the words mean: radiation, radioactive, nuclear radiation
Radiation is a fairly flexible word. We can say that a light bulb radiates light, a speaker radiates sound or a mobile phone radiates microwaves. Radiation is all about sending energy out into the surroundings. This is often in the form of a wave but can also be little particles.
If something is radioactive then it sends out radiation that you can't turn off or affect in any way by any normal means. If something is radioactive then the type of radiation it gives off is called nuclear radiation because it comes from changes in the nucleus of atoms.
Radiation tends to spread out in the surroundings
You can't get rid of energy but it does tend to get spread thinner and thinner and become impossible to detect. This is what happens to all radiation in the end. The energy gets spread so thin that you can't tell it's there any more.
Animation to show radiation as energy spreading out into the environment.If the radiation consists of particles then these particles don't disappear but they do stop moving.
Simulation of how energy is transferred by sound waves. You can turn the sound on and off and watch what happens to the motion of the particles.Detecting nuclear radiation
You need special apparatus like a Geiger counter to detect nuclear radiation. You can't see it, hear it or feel it.
Simple activity about the detection of different types of radiation. You have to match the picture to the description.You can use a Geiger counter to show that nuclear radiation is given off in all directions by something that's radioactive.
Activity You can drag the Geiger counter tube to show that the nuclear radiation is given off in all directions.Irradiation doesn't make something radioactive
When nuclear radiation hits something, like an apple, we say the apple has been irradiated. Irradiating things doesn't make them radioactive. The apple may absorb the energy of the radiation, making it a little warmer, but the apple doesn't start giving off nuclear radiation.
Simple activity to show that when something absorbs radiation it doesn't itself become radioactive.Irradiation can be used to kill bacteria in food so it will last longer.
Nuclear radiation can't be increased, decreased or turned off
Non-nuclear radiation can normally be changed or even turned off.
Animation showing how most sources of non-nuclear radiation can be turned off, in which case the energy spreads out into the environment.But whatever we do we can’t change how much nuclear radiation a radioactive source gives off. The only thing we can do is wait.
We can cool it down, heat it up, blow it to bits or dissolve it in acid but we never destroy the atoms themselves so we never change the amount of radioactivity.
Simple activity to show that you can't do anything to change the amount of nuclear radiation given off.We call something that gives off nuclear radiation ‘radioactive’. So if something is radioactive we can’t turn it off!
Nuclear radiation: difficult to detect, impossible to change
Nuclear radiation can’t be seen, heard or felt and we can’t do anything to change it. So there are two major reasons for making sure radioactive substances are carefully controlled.
Without special instruments you can’t tell that nuclear radiation is there until you notice the harm it is doing and this might be years later. And you can’t change the amount of radiation given off so all you can do is keep the radioactive substance in a safe place.
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