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The graph shows how the activity of a sample of a radioactive material changes with time. The sample has an initial activity of 80 counts per minute. Use the graph to find the half-life of the material. (ii) Another sample of the material has an initial count rate of 40 counts per minute.
HALF-LIFE WORKSHEET Name. Use Reference Table on side to assist you in answering the following questions. Equations: Vs lifes: As-81 = 33 seconds. Au-198 = 2.69 days. C-14 = 5730 years.
13 kwi 2023 · First step: After 1 half-life, N/2 decay, N/2 remain. Second Step: After 2 half-life, 1/2 of N/2 decay, N/4 remain. Third step: After 3 half-life, 1/2 of N/4 decay, N/8 remains. The number of atoms disintegrated = Sum of the disintegrated atoms or fractions. This is now equal to = N/2 + (1/2 x N/2) + (1/2 x N/4) = N/2 + N/4 + N/8 = (7/8)N
A graph can be used to make half-life calculations. The graph shows how the activity of a radioactive sample changes over time. Each time the original activity halves, another half-life has passed. The time it takes for the activity of the sample to decrease from 100% to 50% is the half-life.
Calculating Half-life. The definition of half-life is the time taken for the count rate from a sample to decrease to half the initial value. If we use a radiation detector, such as a Geiger-Muller tube, we can measure the radiation being emitted from a a sample and calculate the radioactive half life from the results.
Half Life Calculations revision video for AQA GCSE Physics and GCSE Combined science. This formula can be used for some of the count rate calculations. Sample question. A radioactive isotope has an initial count rate of 60000Bq, with a half life of 4 minutes. Calculate the count rate after 12 minutes. 12 minutes/4 minutes = 3 half lives.
As a sample of something is decaying and going through half lives, we can measure the activity of the sample. Activity measures the number of nuclei that decay per second (sometimes also called the decay rate). It is usually measured in Becquerels (Bq), which is equal to decays/second.
