Water is cooled from `4^(@)C` to `0^(@)C` it:

Options

A. contracts
B. expands
C. first contracts, then expands
D. first expands, then contracts

Answer

To solve the question regarding the behavior of water as it is cooled from 4°C to 0°C, we can follow these steps:

### Step 1: Understand the behavior of water as it cools
When water is cooled, it generally contracts. This means that the molecules come closer together as the temperature decreases.

**Hint:** Remember that most substances contract when cooled due to reduced molecular motion.

### Step 2: Identify the temperature range
In this specific case, we are cooling water from 4°C to 0°C. At 4°C, water is at its maximum density, and as it cools further to 0°C, it continues to contract until it reaches this temperature.

**Hint:** Think about the properties of water and how it behaves differently at various temperatures.

### Step 3: Consider the molecular interactions
As water cools, the hydrogen bonds between water molecules play a crucial role. At temperatures above 4°C, water molecules are moving more freely, and as they cool, they come closer together due to the hydrogen bonding.

**Hint:** Recall that hydrogen bonds are responsible for the unique properties of water, including its density changes with temperature.

### Step 4: Analyze the transition to ice
When water reaches 0°C, it begins to freeze. However, the process of freezing involves a change in structure where water molecules arrange themselves into a crystalline structure, which is less dense than liquid water. This is why ice floats on water.

**Hint:** Consider how the arrangement of molecules changes when water freezes and how this affects density.

### Conclusion
Thus, when water is cooled from 4°C to 0°C, it contracts until it reaches 0°C. The correct answer to the question is that water contracts when cooled from 4°C to 0°C.

### Summary of Steps:
1. Water generally contracts when cooled.
2. The specific temperature range is from 4°C to 0°C.
3. Hydrogen bonds influence the behavior of water molecules.
4. At 0°C, water begins to freeze, forming ice which is less dense than liquid water.