Question

Mercury is used in thermometers because:

• A. it does not wet the glass
• B. it expands on heating
• C. it is a liquid
• D. all of these

Answer 1

Answer: (D)

all of these

Mercury is shiny liquid metal with high co-efficient of expansion. Keeping high-profile words aside, to put in simple terms,

1. It’s shiny. You can easily see the level of mercury inside a glass thermometer. Imagine using water or any other translucent liquid.
2. It’s sensitive. Heating even on a small scale causes significant expansion in it’s volume which can be made clearly visible on a marked scale.
3. The boiling point of mercury is nearly 674.06 degrees Fahrenheit. So using it in college laboratory or hospitals really doesn’t convert the mercury to vapors.
4. It’s non-sticky. The property of mercury to not stick on glass is a main reason to use it. Unlike water, droplets of mercury never stick on the glass walls of the thermometer.

The correct answer is D.