A sample of a radioactive material has a half-life of 15 minutes15\text{ minutes}15 minutes.
Which statement is correct?
After 10 minutes, more than half of the material has decayed.
After 30 minutes, a quarter of the radioactive material remains.
After 45 minutes, a sixth of the radioactive material remains.
After 60 minutes, all of the radioactive material has decayed.
144 exam-style questions on CIE IGCSE Physics 5.2.4a Half-life. Each one has a worked solution and a mark scheme showing where the marks go.