Theoretical exercise – Feedback 1.

Is it possible that the activity of a radioactive material increases? If not, why not, if yes, under which circumstances?

Theoretical exercise – Feedback 2.

In 1898 the Curies have extracted radium from uranium-ore. (The members of the uranium are in equilibrium in this mineral). At least how much uranium was contained in the bulk of ore, from which 1 g pure radium was produced? (The half-life of the uranium is 4,5 billion years, and that of the radium is 1620 years.)