A radioactive sample is measured to have the number of 7.4 107 at t = 10 min and 2.7 10?

att = 20 min. Determine

1. the initial number of the radioactive sample.
2. the half-life (in min) of the sample.

Express the values to 3 significant figures, if necessary.

B5. A radioactive sample is measured to have the number of 7.4 x 10 at t = 10 min and 2.7 x 10 at t = 20 min. Determine (a) the initial number of the radioactive sample. (3 marks) (b) the half-life (in min) of the sample. (3 marks) Express the values to 3 significant figures, if necessary