Question

Assertion :The size of $N{a}^{+}$ ion is smaller than Na. Reason: $N{a}^{+}$ has same nuclear charge as that of Na.

• A. Assertion and reason both are correct statements and reason is correct explanation for assertion.
• B. Assertion and reason both are correct statements but reason is not correct explanation for assertion.
• C. Assertion is correct statement but reason is wrong statement.
• D. Assertion is wrong statement but reason is correct statement.

Answer 1

The correct option is B Assertion and reason both are correct statements but reason is not correct explanation for assertion.

The ${Na}^{+}$ ion and $Na$ atom have same nuclear charge, because they have the same number of nucleons. However, ${Na}^{+}$ is smaller than $Na$ because it has one electron less, so, it has more effective nuclear charge. Thus, there is more attraction on existing electrons, making $N{a}^{+}$ smaller in size compared to $Na$.