Students should be able to compare the hazards Local rules (10 min) The students should make a plan for a associated with contamination and irradiation. poster or booklet explaining how the radioactive sources Suitable precautions must be taken to protect should be stored and handled and explaining how these against any hazard that the radioactive source precautionary rules reduce harm. They can then produce this used in the process of irradiation may present. booklet as homework. Students should understand that it is important for the findings of studies into the effects of Protect and survive (5 min) Ask students to suggest what radiation on humans to be published and shared would need to be done if one of the radioactive sources was with other scientists so that the findings can be dropped and lost. checked by peer review. Lesson P7.5 Activity and half-life MS: 1b, 1c, 3d, 4a AQA spec link: Aiming for Grade 4 LOs: 4.2.1 Activity is the rate at which a source of State that the activity of a radioactive sample unstable nuclei decays. will fall over time. Activity is measured in becquerel (Bq). Define half-life in simple terms such as time ‘the Count-rate is the number of decays recorded it takes for half of the material to decay’. each second by a detector (e.g., Geiger–Muller Find the half-life of a substance from a of tube). count rate (or nuclei remaining) against time with support.
Students should be able to compare the hazards associated with contamination and irradiation. Suitable precautions must be taken to protect against any hazard that the radioactive source used in the process of irradiation may present. Students should understand that it is important for the findings of studies into the effects of radiation on humans to be published and shared with other scientists so that the findings can be checked by peer review. Local rules (10 min) The students should make a plan for a poster or booklet explaining how the radioactive sources should be stored and handled and explaining how these precautionary rules reduce harm. They can then produce this booklet as homework. Protect and survive (5 min) Ask students to suggest what would need to be done if one of the radioactive sources was dropped and lost. Lesson P7.5 Activity and half-life MS: 1b, 1c, 3d, 4a AQA spec link: 4.2.1 Activity is the rate at which a source of unstable nuclei decays. Activity is measured in becquerel (Bq). Count-rate is the number of decays recorded each second by a detector (e.g., Geiger–Muller tube). Aiming for Grade 4 LOs: State that the activity of a radioactive sample will fall over time. Define half-life in simple terms such as ‘the time it takes for half of the material to decay’. Find the half-life of a substance from a of count rate (or nuclei remaining) against time with support.