Question

in order to decrease radioactive nuclei to one million of its initial number , no of half lives roquire

Answer 1

Answer:

20 half lives required

Explanation:

In order to decrease radioactive nuclei to one million of its initial number , no of half lives required

Let say number of half life required = n

then (1/2)ⁿ  = 1/1 Million

1 Million = 10⁶ = 1000000

=> (1/2)ⁿ = 1/1000000

=> 2ⁿ = 10⁶

Taking Log both sides

log (2ⁿ) = log (10⁶)

=> n Log 2 = 6 Log 10

=> n(0.301) = 6   ( log 10 = 1)

=> n = 6/0.301

=> n = 19.93

=> n ≈ 20

20 half lives required