Activity
Part of the Optics, Waves and Modern Physics section of Coddy's Physics journey. Lesson 47 of 53.
Activity: decays per second, in becquerels.
A = λN, λ = ln 2 / T
λ: the decay constant. Short half-life: big λ.
The activity halves every half-life: A = A₀ (½)^(t/T).
Challenge
A sample holds 10¹² nuclei of iodine-131, whose half-life is 8 days. First find the decay constant λ, then the sample's activity A.
Try it yourself
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
All lessons in Optics, Waves and Modern Physics
1Reflection and Refraction
Reflection of LightThe Refractive IndexSnell's LawTotal Internal ReflectionDispersionApparent DepthRecap - Optical Fiber4Mechanical Waves
What a Wave IsTwo Graphs of a WaveWhen Pulses MeetInterferenceStanding WavesHarmonicsRecap - Guitar String