Question

Assertion :${}_{56}^{133}Ba+e^{-}⟶$ ${}_{55}^{133}Cs+X$-ray.
It is an example of $K$-electron capture. Reason: Atomic number of daughter nuclide decreases by one unit in $K$-electron capture.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Reason is correct but Assertion is incorrect

Answer 1

The correct option is B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

${}_{56}^{133}Ba+e^{-}⟶{}_{55}^{133}Cs+X-ray$

is an example of K-electron capture in Ba due to n/p ratio of ${}_{56}^{133}Ba$ being less than $1.$

This reduce the atomic number.