What do scientists use to measure temperature?

• A. Barometer
• B. Thermometer
• C. Ruler
• D. Hydrometer

Answer: (B)

Scientists use a thermometer to measure temperature because it is specifically designed for that purpose. A thermometer works by utilizing substances that change in physical properties, such as the expansion of liquids like mercury or colored alcohol, in response to temperature changes. This allows for accurate readings of how hot or cold an object or environment is.

Thermometers come in various forms, such as digital or glass, and are commonly used in various fields including weather forecasting, medicine, and scientific research to gauge temperature accurately. This makes the thermometer the appropriate tool for temperature measurement, distinguishing it from other tools that serve different functions, such as the barometer, which measures atmospheric pressure, or a ruler, which measures length. The hydrometer is designed to measure the density of liquids, further illustrating the specificity of the thermometer's function in measuring temperature.