Question

Assertion (A): Atomic size increases along a period.

Reason (R): Effective nuclear charge increases with atomic number.

Options

• Both A and R are true and R is the correct explanation of A.

• Both A and R are true but R is not the correct explanation of A.

• A is true but R is false.

• A is false but R is true.

Answer 1

A is false but R is true.

Explanation:

Atomic size generally decreases from left to right across a period, so A is false. Effective nuclear charge increases across a period, making R true and pulling the electrons closer to the nucleus.