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 the given statements one by one.

### Step-by-Step Solution:

1. **Understanding the Structure of Ice:**
Ice is a solid form of water (H2O) and has a unique crystalline structure. In this structure, each water molecule forms hydrogen bonds with neighboring water molecules.

2. **Analyzing Each Statement:**
- **Statement A: "It has an open cage-like structure."**
- This statement is true. Ice has a crystalline structure that resembles an open cage due to the arrangement of water molecules and the hydrogen bonds between them.

- **Statement B: "It has less density than water."**
- This statement is also true. Ice is less dense than liquid water, which is why ice floats on water.

- **Statement C: "Each oxygen atom is surrounded by 4 hydrogen atoms."**
- This statement is true as well. In the structure of ice, each oxygen atom can form hydrogen bonds with four hydrogen atoms from neighboring water molecules.

- **Statement D: "Each oxygen atom has 4 hydrogen bonds around it."**
- This statement is not true. While each oxygen atom does participate in hydrogen bonding, it does not have four hydrogen bonds directly around it. Instead, each oxygen is involved in hydrogen bonding with two hydrogen atoms from two different water molecules, and the other two hydrogen atoms are involved in hydrogen bonding with other oxygen atoms.

3. **Conclusion:**
The statement that is not true about ice is **Option D: "Each oxygen atom has 4 hydrogen bonds around it."**

### Final Answer:
**Option D is not true about ice.**

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