Question

Which of the following has the longest half-life?

a. 0-19
b. H-3
c. Zn-71
d. Rb-85

Answer 1

b. H-3

Step-by-step explanation:

The half life of the following isotopes is given as;

a. 0-19

26.88 seconds

b. H-3

12 years

c. Zn-71

2.4 minutes

d. Rb-85

This is a stable isotope. It does not decomposes.

Comparing the half lives, the isotope with the longest half life is Hydrogen - 3. With half life of 12 years.