Iodine-131 decay: mass remaining over 45 days

An example figure from the Half-Life Graph generator.

Decay curve of an 80 g sample of iodine-131, mass remaining in grams against time in days, with a dot at the start and at each half-life — An 80 g sample of iodine-131 decaying over 45 days, its mass remaining in grams against time in days. A dot marks the start and each half-life along the curve, at 80, 40, 20, 10, 5 and 2.5 g, for questions on how much is left after a given time.

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Answer key

Iodine-131: half-life 8.02 days, λ = 0.0864 per day; beta decay to xenon-131

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