On which of the following scales of temperature, the temperature is never negative

Options

A. Celsius
B. Fahrenheit
C. Reaumur
D. Kelvin

Explanation

To determine which temperature scale never has negative values, we can analyze each of the given options:

1. **Celsius Scale**:
- The Celsius scale has a freezing point of water at 0°C and a boiling point at 100°C. However, it also extends below 0°C, meaning temperatures can be negative (e.g., -10°C).

2. **Fahrenheit Scale**:
- The Fahrenheit scale has a freezing point of water at 32°F and a boiling point at 212°F. Similar to Celsius, it also includes negative values (e.g., -10°F).

3. **Rankine Scale**:
- The Rankine scale is an absolute temperature scale used in thermodynamics, similar to Kelvin but based on Fahrenheit increments. It starts at absolute zero, which is 0°R, but it can also have negative values in relation to the Fahrenheit scale.

4. **Kelvin Scale**:
- The Kelvin scale is the absolute temperature scale. It starts at absolute zero (0 K), which is theoretically the lowest possible temperature. According to the third law of thermodynamics, it is impossible to reach temperatures below absolute zero. Therefore, the Kelvin scale does not have negative values.

Based on this analysis, the temperature scale that never has negative values is the **Kelvin scale**.

### Final Answer:
The correct answer is **Option 4: Kelvin**.

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