The half life of polonium is 140 days. In what time will 15 g of polonium be disintegrated out of its initial mass of 16 g?

Options

A. 230 days
B. 560 days
C. 730 days
D. 160 days

Answer

B

Explanation

Here, `m_0`=16 g, m=16-15 =1 g
As `m/m_0=(1/2)^n` or `1/16=(1/2)^4=(1/2)^n`
`rArr` n=4
Time taken to disintegrate = `T_(1//2)xxn = 140 xx 4`
=560 days