Question

Assertion :The position of an element in periodic table after emission of one $\alpha$ and two $\beta$-particles remains unchanged. Reason: Emission of one $\alpha$ and two $\beta$-particles gives isotope of the parent element which acquires same position in the periodic table.

• 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. Both Assertion and Reason are incorrect

Answer 1

The correct option is A Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

R.E.F image

The position in the pieriodic table are based on Z.

As z of the element remain the same, its portion

wont change after one $\alpha$ and $z\beta -$ decays

Isotope: two element with same z but different no.of

neutrons and hence A are isotope of each other.