What instrument would you use to measure temperature?

What instrument would you use to measure temperature?

• A. A ruler.
• B. A thermometer.
• C. A scale.
• D. A stopwatch.

Answer: (B)

Temperature is how hot or cold something is, and you measure it with an instrument that responds to heat. A thermometer is designed for this purpose because its material changes in a predictable way as temperature changes—mercury or alcohol expands in a tube, or a digital sensor shows a reading—so you can read a specific temperature value. That’s why it’s the best choice for measuring temperature. Rulers measure length, scales measure mass, and stopwatches measure time, so they wouldn’t tell you how hot or cold something is.

Temperature is how hot or cold something is, and you measure it with an instrument that responds to heat. A thermometer is designed for this purpose because its material changes in a predictable way as temperature changes—mercury or alcohol expands in a tube, or a digital sensor shows a reading—so you can read a specific temperature value. That’s why it’s the best choice for measuring temperature. Rulers measure length, scales measure mass, and stopwatches measure time, so they wouldn’t tell you how hot or cold something is.