A radioisotope has a decay constant of 10^−7s‾¹. The average life of the radioisotope is?

A. 1.00 x 10⁷s
B. 6.93 x 10⁶s
C. 1.00 x 10^-7s
D. 6.93 x 10⁷s

Correct Answer:

Option B = 6.93 x 10⁶s

Explanation

Average life / Half life (T½) = ln2/λ = 0.693/10^-7
= 0.693 x 10⁷
= 6.93 x 10⁶