Question

phosphorus-32 ahs a half-life of 14.0 days. Starting with 8.00 g of 32 P, how many grams will remain after 56.0 days

Answer 1

0.500 grams would be left after 56.0 days.

After 14 days=4.00 g
After 28 days=2.00 g
After 42 days=1.00 g
After 56 days=0.500 g

This is after four half lives.