alpha, beta and gamma radiation what is radiation? starter: why do scientists use symbols? write...

Alpha, Beta and Gamma Radiation

What is radiation?

Starter: why do scientists use symbols? Write down as many as can think of and what

they mean.

Learning Outcomes

• explain that there are three types of radioactive emissions: alpha, beta and gamma

• explain that radioactive elements are unstable and emit alpha or beta particles when they change into other elements

• explain that radioactive behaviour is not changed by chemical or physical processes

Radiation

• Radiation is all around us! This is called background radiation.

What is everything made of ?

Everything is made up of miniscule particles called ATOMS. Inside atoms are even smaller particles.

Can you name the parts of the atom?ELECTRONS orbit the nucleus

This is the NUCLEUS.

PROTONS and NEUTRONS are found in the nucleus

Radioactive elements

• Unstable, radioactive elements give off energy from the nucleus.

• This makes the nucleus more stable.

• Over time the radioactive elements become stable and therefore safe.

Lets investigate

• This is a Geiger counter.• It tells us whether there is radiation around and

what sort of radiation it is.

• Crushing, heating, hiding, reacting or dissolving radioactive elements will NOT reduce the radioactivity.

TYPES OF RADIATION

Radioactive elements are unstable so emit particles to turn into a more stable element. The particles emitted are alpha, beta and gamma.

Alpha

What do you notice?

So, an alpha particle is 2 protons and 2 neutrons.

Beta

A beta particle is a high speed electron

Gamma

These are waves not particles. They have no mass.

PROPERTIESAlpha, Beta and Gamma all have different properties:

• Different strengths

• They travel different distances

• They are stopped by different

materials.

Radioactivity

Copy the diagram below and complete the arrows for each type. Then use the words at the bottom to construct an explanation in your own words.

Alpha, Beta, Gamma, Thick lead, Paper, Aluminium

Now : copy the table.

Deflected by electric and magnetic fields?

Attracted to negative plate.

Attracted to positive plate.

No

Complete the worksheet

Changing Radiation

• Radioactive elements cannot be changed by chemical or physical means. It keeps being radioactive until every atom is stable.

• Think about Chernobyl!

Task

• Produce a revision poster about ionising radiation.

• C- included the 3 types of radiation and described what they are.

• B- as for C but included some additional properties e.g. what they are penetrated by.

• A – as for B but included information on background radiation.

• A* - as for A but considered the dangers of ionising radiation and how we can avoid harm from them.

Quiz2.A stable atom has…

A) Equal numbers of Protons & Electrons

B) Different numbers of Protons

C) Equal numbers of Electrons & Neutrons

D) Equal numbers of Protons & Electrons

Quiz

3.How many types of radiation are there?

A) 3

B) 9

C) 2

D) 4

Quiz

4.Radiation is emitted from…

A) All atoms

B) Most atoms

C) Unstable atoms

D) Stable atoms

Quiz

5.An alpha particle consists of…

A) 2 protons

B) A high speed electron

C) A wave

D) 2 protons and 2 neutrons

Quiz

6.Beta radiation is…

A) 2 protons

B) A high speed electron

C) A wave

D) 2 protons and 2 neutrons

Quiz

7.Gamma radiation is…

A) 2 protons

B) A high speed electron

C) A wave

D) 2 protons and 2 neutrons

Quiz

8.Alpha is stopped by…

A) Thick lead

B) Thin paper

C) A few cm of air

D) Aluminium

Quiz

9.Beta is stopped by…

A) Aluminium

B) Paper

C) Lead

D) Concrete

Quiz

10. Gamma is mostly stopped by…

A) A few cm of air

B) Thick lead

C) Aluminium

D) Paper