Which three temperature readings all mean the same thing? A. 373 Kelvin, 100 degrees Celsius, 273 degrees Fahrenheit. B. 273 Kelvin, 100 degrees Celsius, 212 degrees Fahrenheit. C. 100 Kelvin, 0 degrees Celsius, 32 degrees Fahrenheit. D. 273 Kelvin, 0 degrees Celsius, 32 degrees Fahrenheit.
The correct answer and explanation is:
The correct answer is D. 273 Kelvin, 0 degrees Celsius, 32 degrees Fahrenheit.
Explanation:
Temperature scales—Kelvin (K), Celsius (°C), and Fahrenheit (°F)—are different ways of measuring thermal energy, but they can be converted into one another. Understanding the relationship between these scales is crucial for interpreting temperature readings correctly.
Key reference points:
- Water freezing point:
- 0 °C
- 273 K
- 32 °F
- Water boiling point:
- 100 °C
- 373 K
- 212 °F
Why answer D is correct:
- 273 Kelvin corresponds exactly to 0 degrees Celsius because the Kelvin scale starts at absolute zero (−273.15 °C). So to convert Celsius to Kelvin, you add 273.15 (rounded here to 273 for simplicity).
- 32 degrees Fahrenheit is the freezing point of water, which matches 0 °C and 273 K.
Thus, 273 K = 0 °C = 32 °F all represent the freezing point of water.
Why other options are incorrect:
- Option A: 373 K, 100 °C, 273 °F
- 373 K = 100 °C (boiling point of water) ✓
- 273 °F is NOT the boiling point of water; 273 °F is about 134 °C. So this is incorrect.
- Option B: 273 K, 100 °C, 212 °F
- 273 K = 0 °C, not 100 °C
- 212 °F = 100 °C (boiling point of water)
So these three do not match.
- Option C: 100 K, 0 °C, 32 °F
- 100 K = −173.15 °C, very cold temperature, nowhere near 0 °C
- 0 °C = 32 °F, so only two match here.
Temperature conversion formulas for clarity:
- Celsius to Kelvin: K=°C+273.15K = °C + 273.15
- Celsius to Fahrenheit: °F=95×°C+32°F = \frac{9}{5} \times °C + 32
- Kelvin to Fahrenheit: °F=95×(K−273.15)+32°F = \frac{9}{5} \times (K – 273.15) + 32
Summary:
Only 273 K, 0 °C, and 32 °F represent the same physical temperature — the freezing point of water. The other sets either mix different temperature points or have incorrect conversions. This makes Option D the only correct choice.