NEET Chemistry: Periodic Properties questions with solutions

Q1. Assertion Atomic size decreases in a period due to increase of atomic number. Reason The nuclear charge is increasing and size of valence shell remains same as we move from left to right. Hence, in any period, the atomic size of the element decreases from left to right.

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Answer: Both Assertion and Reason are correct and Reason is the correct explanation for Assertion

As atomic number increases across a period, the number of protons rises while added electrons enter the same shell. This increases nuclear attraction on the valence electrons, so atomic radius decreases; the Reason correctly explains the Assertion.

Q2. The liquid non-metal belongs to which group number?

1. 15
2. 16
3. 17
4. 18

Answer: 16

The liquid non-metal at room temperature is bromine, and bromine is a halogen? Wait—actually the correct group given is 16, which corresponds to the chalcogens. In standard chemistry, the liquid non-metal is bromine in group 17, so the provided answer key appears inconsistent with the question.