Which of the following properties are in the increasing order from top to bottom for metal ions in Group 1?

Options

A. Ionic radius
B. Hydrated radius
C. Ionic mobility
D. Hydration number

Answer

To determine the increasing order of properties for metal ions in Group 1 from top to bottom, we need to analyze the following properties: ionic radius, hydration radius, ionic mobility, and hydration number.

### Step-by-Step Solution:

1. **Understanding Ionic Radius**:
- In Group 1 (alkali metals), the ionic radius increases as you move down the group. This is due to the addition of extra electron shells, which outweighs the effect of increasing nuclear charge.
- **Conclusion**: Ionic radius increases from Li+ to Cs+.

2. **Understanding Hydration Radius**:
- The hydration radius is the effective radius of an ion when it is surrounded by water molecules. As the ionic radius increases, the hydration radius generally decreases because larger ions have a lower charge density and attract fewer water molecules.
- **Conclusion**: Hydration radius decreases from Li+ to Cs+.

3. **Understanding Ionic Mobility**:
- Ionic mobility refers to how easily an ion can move through a solution. As the ionic radius increases, the mobility of the ion also increases because larger ions can move more freely through the solvent.
- **Conclusion**: Ionic mobility increases from Li+ to Cs+.

4. **Understanding Hydration Number**:
- The hydration number refers to the number of water molecules that surround an ion. As the ionic radius increases, the hydration number tends to decrease because larger ions can accommodate fewer water molecules due to their lower charge density.
- **Conclusion**: Hydration number decreases from Li+ to Cs+.

### Summary of Increasing Order:
- **Ionic Radius**: Increases from Li+ to Cs+
- **Hydration Radius**: Decreases from Li+ to Cs+
- **Ionic Mobility**: Increases from Li+ to Cs+
- **Hydration Number**: Decreases from Li+ to Cs+

### Final Order from Top to Bottom:
1. Hydration Radius (decreases)
2. Hydration Number (decreases)
3. Ionic Radius (increases)
4. Ionic Mobility (increases)