7.1 Nuclear Reactions

What are atoms made of?Which particles are found in the nucleus?What are the three types of ionising radiation?What are the three types made of?

April 21, 2023

Alpha, Protons, Electrons, Gamma, EM wave, Neutrons, Beta.

7.1 Nuclear Reactions1) What are atoms made of?

Protons, Neutrons, Electrons2) Which particles are found in the nucleus?

Protons, Neutrons3) What are the three types of ionising radiation?

Alpha, Beta, Gamma4) What are the three types made of?

Alpha = 2Protons + 2NeutronsBeta = ElectronGamma = High Energy EM wave

April 21, 2023

7.1 Nuclear Reactions

• Alpha emission reduces the mass number by 4 and the proton number by 2.

• Beta emission increases the proton number by 1 and mass does not change.

• Background radiation is everywhere emitted from cosmic rays and rocks.

April 21, 2023

Uranium is a radioactive element found naturally in many rocks. It is the heaviest naturally occurring element, around 238 times heavier than Hydrogen. It is used to date how old rocks are and for nuclear power stations.

Page 198 AQA Physics

Alpha

• An alpha particle contains 2 protons and 2 neutrons. This gives the particle an atomic mass of 2+2 = 4.

XAtomic mass

Proton number

Symbol

α4

2

Alpha decay

Thorium 228 is an alpha emitter forming radium 224. This can be shown in this equation:

α4

2

Ra224

88Th

228

90+

P198 Answer question b

Beta

• Beta particles are electrons emitted from the nucleus. This causes a neutron to change into a proton so there is an extra proton in the nucleus.

XAtomic mass

Proton number

Symbol

Beta decay

Potassium 40 decays by a Beta emission forming Calcium 40.

β0

-1

Ca40

20K

40

19

+P199 Answer question cβ

0

-1

Gamma• This is a type of electromagnetic

wave and so has no mass. The element does not change but loses energy to become more stable.

P199 Answer the summary questions

7.1 Nuclear Reactions

• Alpha emission reduces the mass number by 4 and the proton number by 2.

• Beta emission increases the proton number by 1 and mass does not change.

• Background radiation is everywhere emitted from cosmic rays and rocks.

April 21, 2023

Uranium 238 is a radioactive element found naturally in many rocks. It is the heaviest naturally occurring element, around 238 times heavier than Hydrogen. It is used to date how old rocks are and for nuclear power stations.