A source contains two phosphorous radio nuclides ^{32}_{15}P\, (T_ | Filo
filo Logodropdown-logo

Class 12


Cell: Structure and Functions


view icon596
like icon150

A source contains two phosphorous radio nuclides and . Initially, 10% of the decays come from . How long one must wait until 90% to do so?

Solution: Let the number of atoms of be and atoms of be .
The decay constants of two atoms be and respectively.

The initial activity of is times that of .

Therefore, we can write the decay constants as: 

Let after time t the activity of be times that of


Now. Divide equation (ii) by (i) and taking the natural log of both sides we get

where and

t comes out to be days
view icon596
like icon150
filo banner image

Connecting you to a tutor in 60 seconds.

Get answers to your doubts.

playstore logoplaystore logo
Similar Topics
cell cycle and cell division
cell: the unit of life