Which information can be determined using half-life? 1)age of material 2)type of particle released 3)percentage of rock that has aged 4)number of radioactive particles left

Half-life is used to determine the age of the material

The radioactive materials are always in the state of decay by losing their energy in the form of rays. The term half-life is used to measure their age after the specific time. Half-life is actually the time which is taken by the radioactive materials to reduce half its initial value and use to measure the age of elements. It is donated as t1/2.

For example, 10 g Barium-139 takes 86 mints to convert int 5g Barium-139 and 5g Lanthanum-139. This time of decay is different in the different element and tells their age after the specific time period. So, the right option is (1).