Question

A certain radioactive isotope has a half-life of 5 days. If one is to make a table showing the half-life decay of a sample of this isotope from from 32 grams to a 1 gram

Answer 1

It will take 25 days for this substance to become 1gram from 32 grams.

Explanation:

Radioactivity or radioactive decay is the process of formation of different element from one Radioactive element due to decay of the radioactive nucleus. The radioactive decay is a first order kinetic reaction. This reaction has a straight log C vs T graph.

Here in this particular reaction, the half life of the radioactive substance is 5 days. So within 5 days, the concentration of the substance becomes halved.

Now, in the sample the amount of substance present = 32 grams

The final amount of this sample = 1 grams.

So number of half lives needed for this decay = 5 half lives.

So number of days required for this decay = $5\times5$ =25.

So within 25 days, 32 grams of the substance becomes 1grams.