Which of the following properties make mercury an ideal liquid for making thermometers?

Options

A. It is easily visible.
B. it expands on heating
C. Its boiling point is high.
D. All of these

Explanation

To determine which properties make mercury an ideal liquid for making thermometers, we can analyze the characteristics of mercury in detail.

### Step-by-Step Solution:

1. **High Boiling Point**:
- Mercury has a high boiling point of 357 degrees Celsius. This property is crucial because thermometers are often used to measure temperatures that can reach up to 200 or even 300 degrees Celsius. If the liquid in the thermometer had a low boiling point, it would vaporize and give inaccurate readings.

**Hint**: Consider why a liquid with a low boiling point would not be suitable for high-temperature measurements.

2. **Visibility**:
- Mercury is a shiny, metallic liquid that is easily visible against the glass of the thermometer. This visibility allows for easy reading of the temperature scale, which is essential for accurate measurements.

**Hint**: Think about how important it is to see the liquid clearly when taking a temperature reading.

3. **Expansion on Heating**:
- Mercury expands uniformly when heated. This means that as the temperature increases, the mercury will rise in the thermometer in a consistent manner, allowing for precise readings. This property is vital for the accuracy of the thermometer.

**Hint**: Reflect on how uniform expansion affects the reliability of temperature readings.

4. **Non-Wetting Property**:
- Mercury does not wet the glass, which means it does not stick to the sides of the thermometer. This ensures that the mercury returns to its original level when the temperature drops, allowing for repeated measurements without residue affecting the readings.

**Hint**: Consider how a liquid that sticks to the sides of a container would impact the measurement process.

5. **Conclusion**:
- Given these properties—high boiling point, visibility, uniform expansion, and non-wetting nature—mercury is indeed an ideal liquid for thermometers. Therefore, the correct answer to the question is that all of these properties make mercury suitable for use in thermometers.

### Final Answer:
All of the above properties make mercury an ideal liquid for making thermometers.