What is not true about ice ?

Options

A. It has open cage like structure
B. It has less density than water
C. Each O atom is surrounded by 4 H atoms
D. Each O atom has four H-bonds around it

Explanation

To determine what is not true about ice, we will analyze some common statements regarding its properties and structure.

### Step-by-Step Solution:

1. **Understanding the Structure of Ice**:
Ice is formed when water freezes, and its structure is characterized by hydrogen bonding between water molecules. Each water molecule (H₂O) has a bent shape due to the two hydrogen atoms being bonded to the oxygen atom, which has two lone pairs of electrons.

**Hint**: Recall that hydrogen bonding occurs between the hydrogen atom of one water molecule and the oxygen atom of another.

2. **Density of Ice**:
One of the well-known properties of ice is that it is less dense than liquid water. This is why ice floats on water. The open cage structure formed by hydrogen bonds creates more space between the molecules in ice compared to liquid water.

**Hint**: Think about how the arrangement of molecules in ice differs from that in liquid water.

3. **Hydrogen Bonding**:
In ice, each oxygen atom is surrounded by four hydrogen atoms due to the hydrogen bonds formed with neighboring water molecules. However, it is important to note that each oxygen atom can only form two covalent bonds with hydrogen atoms. The additional hydrogen atoms are involved in hydrogen bonding, which is a weaker interaction compared to covalent bonds.

**Hint**: Differentiate between covalent bonds and hydrogen bonds when considering the structure of ice.

4. **Evaluating Statements**:
- **Statement A**: Ice has an open cage structure. (True)
- **Statement B**: Ice has a density less than that of water. (True)
- **Statement C**: Each oxygen atom is surrounded by four hydrogen atoms. (False, because while there are four hydrogen atoms involved in interactions, only two are covalently bonded to the oxygen atom.)
- **Statement D**: Each oxygen atom forms two covalent bonds with hydrogen. (True)

**Hint**: Identify which statements are based on covalent bonding versus hydrogen bonding.

5. **Conclusion**:
The statement that is not true about ice is that each oxygen is surrounded by four hydrogen atoms in terms of covalent bonding. This is incorrect because an oxygen atom can only form two covalent bonds with hydrogen atoms, while the other interactions are due to hydrogen bonding.

### Final Answer:
The statement that is not true about ice is: "Each oxygen is surrounded by four hydrogen atoms."