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Nuclei

Question
CBSEENPH12040161

The half-life period of a radioactive element X is the same as the mean life of another radioactive element Y. Initially, both of them have the same numbers of atoms then,

  • X and Y have the same decay rate initially

  • X and Y decay at the same rate always

  • Y will decay at a faster rate than X

  • X will decay at a faster rate than Y

Solution

C.

Y will decay at a faster rate than X

The half-life of x - mean life of y

Let λx and λy be decay constants of x and y, then condition (1) implies

0.693λx = 1λyλy = λx0.693 λy > λx

As rate of decay αλ; hence decay of y will be faster than that of x.