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

because u need two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei to form isotopes.

so since they all have the same shape? i mean maybe because m& m and reeses are both chocolates