NEET Physics Nuclei Questions Solved

NEET - 2011

The half-life of a radioactive isotope X is 50 yr.

It decays to another element Y which is stable.

The two elements X and Y were found to be in 

the ratio of 1:15 in a sample of a given rock.

The age of rock was estimated to be

(a) 200 yr

(b) 250 yr

(c) 100 yr

(d) 150 yr

We know that

            NN0=12t/t12116=12t/50t=4×50t=200 yr

 

Difficulty Level:

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