Chapter 8, Problem 1VSC

To determine

The most radioactive element among.

1. Uranium −235
2. Potassium −40M
3. Both are equally radioactive

Answer to Problem 1VSC

The most radioactive element is uranium $-235$.

Explanation of Solution

Introduction:

Radioactive elements emit radiation and decays by themselves.

The half-life of radioactive substance is the time taken by a substance to decay half of its original value. A radioactive isotope with lower half-life decays fast as compared to another radioactive isotopes.

The given plot shows that uranium $-235$ has half-life of less than $1$ unit and potassium $-40$ has a half-life of $1.25$ units.

So, the most radioactive element is uranium $-235$ correct answer is (a).

Conclusion:

The most radioactive element is uranium $-235$.