1. Ionising Radiation

2. Introduction to Radioactivity
Some substances are classed as “radioactive” – this means that they are unstable and continuously give out radiation:
Radiation
The nucleus is more stable after emitting some radiation – this is called “radioactice decay” and the activity is measured in “Becquerels (Bq)”.
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3. Some Isotopes are radioactive
A radioactive substance has an unstable nucleus.
The unstable nucleus can become more stable by losing energy (it decays).
It loses energy by emitting 3 types of ionising radiation.
You cannot predict when a nucleus will decay:- it is a random process

4. Types of radiation
1) Alpha () – an atom decays into a new atom and emits an alpha particle (2 protons and 2 ______ – the nucleus of a ______ atom)
Unstable nucleus
New nucleus
Alpha particle
2) Beta () – an atom decays into a new atom by changing a neutron into a _______ and electron. The fast moving, high energy electron is called a _____ particle.
Beta particle
New nucleus
Unstable nucleus
3) Gamma – after  or  decay surplus ______ is sometimes emitted. This is called gamma radiation and has a very high ______ with short wavelength. The atom is not changed.
Words – frequency, proton, energy, neutrons, helium, beta
Unstable nucleus
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New nucleus
Gamma radiation

5. There are three types of nuclear radiation:
Alpha
Beta
Gamma

6. Alpha particle
An alpha particle consists of two protons and two neutrons

7. A beta particle (fast moving electron that)

8. Gamma rays
Gamma rays are high frequency electromagnetic waves

9. Alpha
Beta
Gamma
All three types of radiation are known as ionising radiation. Ionisation radiation is radiation that has enough energy to knock out electrons from atoms and change them to IONS.

10. Properties of alpha, beta and gamma radiation
Name
What is it
Relative Charge
Relative Mass

11. Properties of alpha, beta and gamma radiation

12. Properties of alpha, beta and gamma radiation
Range in air
Type of Radiation
Range in air
alpha
a few centimetres
beta
1- 2 metres
gamma
very long range
Note:- the amount of energy the radiation has when emitted determines how far it will travel through the air and what it can penetrate through.