1) 239pu has a half-life of 24000 years. if we have 10 g of 239pu, how many grams will be left after 75000 years? answer in units of g. 2) the half-life of 137ce is 30 years. how many grams of 137ce must be produced now to have a sample containing 37 g of 137ce 160 years from now? answer in units of g.

1)

There are half lives in a period of 75,000 years. The sample of plutonium-239 would thus expect a loss in mass that would results in a mass ratio of which is the same as relative to the initial mass. of plutonium-239 would thus remain in the initial sample after 75,000 years.

2)

There are half lives in 160 years.

Thus

answer; natural resources;