Nitrogen , oxygen and fluorine are the highly electronegative elements. When they are tied to a hydrogen atom to form covalent bond, the electrons of the covalent bond are shifted towards the more electronegative atom.This partially positively charged hydrogen atom forms a bond with the other electronegative atom. This bond is called as hydrogen bond and is weaker than covalent bond.For example, in HF molecule, the hydrogen bond exists between hydrogen atom of one molecule and fluorine atom of another molecule as depicted
`---H^(delta+)-F^(delta-)---H^(delta+)-F^(delta-)---H^(delta+)-F^(delta-)`
Here, hydrogen bond acts as bridge between atoms which holds one atom by covalent bond and the other by hydrogen bond.Hydrogen bond is represented by a dotted line (---) while a solid line represents the covalent bond. Thus, hydrogen bond can be defined as the attractive force which binds hydrogen atom of one molecule with the electronegative atom (F,O and N) of another molecule.
What statement is incorrect about `D_2O` (solid)

Options

A. It will float in `D_2O` liquid
B. It will sink in `H_2O` liquid
C. It has maximum density at `4^@C`
D. It has less volume than `H_2O` solid for same mass of both compound

Explanation

To determine which statement about D₂O (solid) is incorrect, we will analyze each statement based on the properties of D₂O and its behavior compared to H₂O.

### Step-by-Step Solution:

1. **Statement A: D₂O will float on D₂O liquid.**
- **Analysis:** D₂O solid has a lower density than D₂O liquid. Therefore, it will float on the liquid.
- **Conclusion:** This statement is **correct**.

2. **Statement B: D₂O will sink in H₂O liquid.**
- **Analysis:** D₂O solid is denser than H₂O liquid. Since it has a higher density, it will sink in H₂O liquid.
- **Conclusion:** This statement is **correct**.

3. **Statement C: D₂O has maximum density at 4°C.**
- **Analysis:** D₂O actually has its maximum density at around 11.4°C, not at 4°C. This is a crucial point because it contradicts the common property of water (H₂O) which has maximum density at 4°C.
- **Conclusion:** This statement is **incorrect**.

4. **Statement D: D₂O has lesser volume than H₂O solid for the same mass of both compounds.**
- **Analysis:** Since density is mass divided by volume, and D₂O is denser than H₂O solid, it will occupy a lesser volume for the same mass.
- **Conclusion:** This statement is **correct**.

### Final Conclusion:
The incorrect statement about D₂O (solid) is **Statement C**, which claims that D₂O has maximum density at 4°C.

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