Decay rate,k is 4.8% per year=-0.048. What is the half-life in years

Answer 1

fraction remaining = 0.5ⁿ where n = no. of half lives

after 1 yr, you have 0.952 remaining (0.048 decayed). Thus...

0.952 = 0.5ⁿ

n = 0.071

This means that 1 year = 0.071 half lives

0.071/1 yr = 0.5/x yr

x = 7.04 years = one half life