Question

Assertion: For hydrogen like species, energy of an electron in a particular orbit increases with increase in value of Z.
Reason: Electronegativity decreases across a period from left to right.

• A. Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
• B. Both Assertion and Reason are true and Reason is not the correct explanation of Assertion.
• C. Assertion is true but Reason is false
• D. Both Assertion and Reason are false

Answer 1

The correct option is C Assertion is true but Reason is false

For hydrogen like species, energy of an electron in $n^{th}$ orbit is given by
$E_n=-\frac{Z^{2}hcR}{n^2}=-13.6\frac{Z^2}{n^2}eV$
where,
R is Rydberg's constant
Z is charge on nucleus

i.e., $E_n\propto Z^2$
Thus, assertion is correct.

Electronegativity increase across the period with decrease in size of atom.

Hence, option (c) is the correct answer.