Question

Assertion (A): Actinoids show wide range of oxidation states.
Reason (R): Actinoids are radioactive in nature.

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

Hint:

Both statements must be checked for truth, and then we check whether the Reason actually explains the Assertion.

Answer 1

The Correct Option is B

Step 1: Understand the format.
We check both statements for truth and then see if the Reason explains the Assertion.

Step 2: Check the Assertion.
Actinoids do show a wide range of oxidation states because the 5f, 6d and 7s orbitals are close in energy, so many electrons can take part in bonding. So the Assertion is TRUE.

Step 3: Check the Reason.
Actinoids are indeed radioactive in nature. So the Reason is also TRUE.

Step 4: Test the explanation link.
The wide range of oxidation states comes from the closeness in energy of the 5f, 6d and 7s orbitals, not from radioactivity. Radioactivity is a separate property. So the Reason does NOT explain the Assertion.

Step 5: Conclude.
Both A and R are true but R is not the correct explanation of A, which is option 2.

\[ \boxed{\text{Both A and R true; R is not the correct explanation}} \]