For same mass of water and ice, why ice floats over water? (A)solids have lesser density than liquids (B)it has open - cage like structure in which lesser molecules are packed per mL than water (C)ice is lighter than water (D) when ice is formed water molecules come closer and start floating.

Options

A. solids have lesser density than liquids
B. it has open - cage like structure in which lesser molecules are packed per mL than water
C. ice is lighter than water
D. when ice is formed water molecules come closer and start floating.

Explanation

To answer the question of why ice floats over water, we need to analyze the properties of both substances, particularly their densities.

### Step-by-Step Solution:

1. **Understanding Density**:
- Density is defined as mass per unit volume (Density = Mass/Volume). Generally, solids are denser than liquids, but water is an exception.

2. **Density of Water and Ice**:
- The density of water at 4°C is approximately 1 g/mL. As water cools down to 0°C and freezes into ice, its density decreases. Ice has a density of about 0.92 g/mL.

3. **Why Ice Floats**:
- Since ice is less dense than water, it will float. Objects that are less dense than the fluid they are placed in will float, while those that are denser will sink.

4. **Structure of Ice**:
- Ice forms a unique open-cage like structure due to hydrogen bonding between water molecules. This structure means that there are fewer water molecules packed into a given volume of ice compared to liquid water, contributing to its lower density.

5. **Conclusion**:
- Therefore, the reason ice floats on water is that it has a lower density than liquid water due to its open-cage structure.

### Answer Selection:
- The correct answer is **(B)**: it has an open-cage like structure in which fewer molecules are packed per mL than water.