1000 tiny mercury droplets coalesce to form a bigger drop .In this process , the temperature of the drop

Options

A. decreases
B. increases
C. does not change
D. may increase or decrease depending upon the size of the drop

Answer

To solve the problem of what happens to the temperature of a mercury drop when 1000 tiny droplets coalesce into a bigger drop, we can follow these steps:

### Step 1: Understand the Process of Coalescence
When multiple small droplets of mercury come together to form a larger droplet, this process is known as coalescence. During this process, the surface area of the droplets decreases.

**Hint:** Consider how the surface area changes when smaller droplets combine into a larger one.

### Step 2: Analyze the Energy Changes
As the tiny droplets merge, the potential energy associated with the surface tension of the droplets decreases. This is because the surface area of the larger droplet is less than the total surface area of the individual droplets combined.

**Hint:** Recall the relationship between surface area and potential energy in the context of surface tension.

### Step 3: Relate Energy to Temperature
The decrease in potential energy during the coalescence process is converted into internal energy of the larger droplet. Since the internal energy of a substance is directly related to its temperature, an increase in internal energy implies an increase in temperature.

**Hint:** Think about how energy transfer affects temperature in a system.

### Step 4: Conclusion
Since the internal energy of the larger droplet increases due to the energy released from the decrease in surface area, the temperature of the drop will also increase. Therefore, the correct answer is that the temperature of the drop increases.

**Final Answer:** The temperature of the drop increases.