Why is the structure of ice porous ?

Answer

### Step-by-Step Solution:

1. **Understanding the Composition of Ice**:
- Ice is primarily composed of water (H₂O). Each water molecule consists of two hydrogen atoms and one oxygen atom.

2. **Molecular Arrangement in Ice**:
- In the solid state, water molecules arrange themselves in a specific pattern. The arrangement is not random; rather, it forms a structured lattice.

3. **Hydrogen Bonding**:
- Water molecules are polar, meaning they have a partial positive charge on the hydrogen atoms and a partial negative charge on the oxygen atom. This polarity leads to hydrogen bonding between water molecules.
- Each water molecule can form up to four hydrogen bonds with neighboring water molecules.

4. **Formation of Cage-like Structure**:
- The hydrogen bonds create a three-dimensional network that holds the water molecules in a fixed position. This network results in a cage-like structure.
- The arrangement of these hydrogen bonds creates open spaces or pores within the structure of ice.

5. **Porosity of Ice**:
- The presence of these open spaces or pores is what makes ice less dense than liquid water. This is why ice floats on water.
- The porous structure is a direct consequence of the hydrogen bonding and the arrangement of water molecules in the solid state.

6. **Conclusion**:
- The structure of ice is porous due to the hydrogen bonding between water molecules, which leads to the formation of a cage-like arrangement with open spaces.