Given below are two statements : Statement (I) : The 4 f and 5 f - series of elements are placed separately in the Periodic table to preserve the principle of classification. Statement (II) : S-block elements can be found in pure form in nature. In the light of the above statements, choose the most appropriate answer from the options given below :

Statement I is true but Statement II is false

Statement I is false but Statement II is true

Both Statement I and Statement II are true

Both Statement I and Statement II are false

Periodic Table and Periodicity PYQ — JEE Main 2024 · 27 Jan · Shift 1 · Q10 with Solution

View written solutionFree

Correct answer: C

Evaluate Statement (I)

Statement (I): The $4f$ and $5f$ series of elements are placed separately in the Periodic table to preserve the principle of classification.
- The $4f$ series corresponds to lanthanoids and the $5f$ series corresponds to actinoids.
- These elements actually belong to periods 6 and 7 respectively, but if they were placed in the main body of the periodic table, the table would become very wide and the regular arrangement into groups would be disturbed.
- Therefore, they are shown separately at the bottom to maintain the systematic classification and compactness of the periodic table.
Hence, Statement (I) is true.
Evaluate Statement (II)

Statement (II): S-block elements can be found in pure form in nature.
- The s-block elements include alkali metals and alkaline earth metals.
- These are highly reactive due to low ionization enthalpy.
- Because of their high reactivity, they are not found in free (pure) form in nature; they occur only in combined state, such as oxides, halides, carbonates, sulfates, etc.
Hence, Statement (II) is false.
Choose the correct option
- Statement (I) = True
- Statement (II) = False
Therefore, the correct option is:

$\boxed{\text{C: Statement I is true but Statement II is false}}$
Comparison with stored answer
- Derived answer: C
- Stored correct answer: C
They match.

View written solutionFree

Correct answer: C

Evaluate Statement (I)

Statement (I): The $4f$ and $5f$ series of elements are placed separately in the Periodic table to preserve the principle of classification.
- The $4f$ series corresponds to lanthanoids and the $5f$ series corresponds to actinoids.
- These elements actually belong to periods 6 and 7 respectively, but if they were placed in the main body of the periodic table, the table would become very wide and the regular arrangement into groups would be disturbed.
- Therefore, they are shown separately at the bottom to maintain the systematic classification and compactness of the periodic table.
Hence, Statement (I) is true.
Evaluate Statement (II)

Statement (II): S-block elements can be found in pure form in nature.
- The s-block elements include alkali metals and alkaline earth metals.
- These are highly reactive due to low ionization enthalpy.
- Because of their high reactivity, they are not found in free (pure) form in nature; they occur only in combined state, such as oxides, halides, carbonates, sulfates, etc.
Hence, Statement (II) is false.
Choose the correct option
- Statement (I) = True
- Statement (II) = False
Therefore, the correct option is:

$\boxed{\text{C: Statement I is true but Statement II is false}}$
Comparison with stored answer
- Derived answer: C
- Stored correct answer: C
They match.