JEE Chemistry 2024 Question with Solution

Given: Two statements about the periodic table and $s$-block elements.

Find: Which option correctly identifies the truth values of Statement I and Statement II.

For Statement I, the $4f$ and $5f$ series correspond to lanthanides and actinides. These are placed separately from the main body of the periodic table to preserve the overall classification pattern and keep the table manageable. Therefore, Statement I is true.

For Statement II, $s$-block elements are highly reactive and therefore are not generally found in pure form in nature. They usually occur in combined form as compounds. Therefore, Statement II is false.

Hence, the correct conclusion is: Statement I is true but Statement II is false.

The correct option is C.

Given:

• Statement I concerns the separate placement of the $4f$ and $5f$ series.
• Statement II concerns the occurrence of $s$-block elements in nature.

Find: The most appropriate option.

1. Statement I: The $4f$ and $5f$ series are the lanthanides and actinides.

2. These elements are shown separately at the bottom of the periodic table.

3. This arrangement helps preserve the principle of classification and avoids making the periodic table excessively wide.

4. So, Statement I is true.

5. Statement II: $s$-block elements include alkali metals and alkaline earth metals.

6. These elements are highly reactive because they lose electrons easily.

7. Due to this high reactivity, they are usually found in combined state, not in pure elemental form, in nature.

8. So, Statement II is false.

Therefore, the correct option is C: Statement I is true but Statement II is false.