1. 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? 04 December 2015 Alpha, Protons, Electrons, Gamma, EM wave, Neutrons, Beta.

2. 7.1 Nuclear Reactions 1) What are atoms made of? Protons, Neutrons, Electrons 2) Which particles are found in the nucleus? Protons, Neutrons 3) What are the three types of ionising radiation? Alpha, Beta, Gamma 4) What are the three types made of? Alpha = 2Protons + 2Neutrons Beta = Electron Gamma = High Energy EM wave 04 December 2015

3. 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. 04 December 2015 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

4. Alpha An alpha particle contains 2 protons and 2 neutrons. This gives the particle an atomic mass of 2+2 = 4. X Atomic mass Proton number Symbol α 4 2 Alpha decay Thorium 228 is an alpha emitter forming radium 224. This can be shown in this equation: α 4 2 Ra 224 88 Th 228 90 + P198 Answer question b

5. 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. X Atomic mass Proton number Symbol Beta decay Potassium 40 decays by a Beta emission forming Calcium 40. β 0 Ca 40 20 K 40 19 + P199 Answer question c β 0

6. 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. 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. 04 December 2015 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.