Which of the following statement is correct for s-block elements:

Options

A. Be has smallest atomic size in IIA group
B. Li is most metallic
C. Mg impart red colour to the flame
D. Cs is most reducing in water

Answer

To determine which statement is correct for s-block elements, we need to analyze the properties of these elements based on their group classifications.

### Step-by-Step Solution:

1. **Identify the S-Block Elements**:
- The s-block elements include Group 1 (alkali metals) and Group 2 (alkaline earth metals).
- Group 1 elements: Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Cesium (Cs), Francium (Fr).
- Group 2 elements: Beryllium (Be), Magnesium (Mg), Calcium (Ca), Strontium (Sr), Barium (Ba), Radium (Ra).

**Hint**: Remember that s-block elements have their outermost electrons in the s orbital.

2. **Understanding Atomic Size**:
- Atomic size increases down a group due to the addition of electron shells.
- Among the alkaline earth metals, Beryllium (Be) is the smallest due to its position at the top of Group 2.

**Hint**: Recall that atomic size trends are influenced by the number of electron shells and effective nuclear charge.

3. **Ionization Energy and Metallic Character**:
- Ionization energy decreases down a group; thus, lithium has a higher ionization energy compared to cesium, making it less metallic.
- The metallic character increases down the group, meaning cesium is more metallic than lithium.

**Hint**: Consider how ionization energy relates to the ability of an element to lose electrons.

4. **Flame Colors**:
- Magnesium (Mg) does not impart a red color to the flame; instead, lithium (Li) gives a crimson red color.
- Therefore, the statement about magnesium imparting red color is incorrect.

**Hint**: Familiarize yourself with flame test colors for different elements.

5. **Reducing Nature in Water**:
- Reducing nature refers to the ability of an element to donate electrons. Lithium, being smaller, has a higher hydration enthalpy and is more reducing than cesium.
- Thus, the statement that cesium is the most reducing in water is incorrect.

**Hint**: Understand the relationship between atomic size and reducing power in aqueous solutions.

6. **Conclusion**:
- After analyzing the statements, the correct statement is that "Beryllium has the smallest atomic size in Group 2."

### Final Answer:
The correct statement for s-block elements is: **Beryllium has the smallest atomic size in Group 2.**