Question

Why is the fluid in a barometer mercury, rather than water or another liquid?

A) Mercury has a higher density than water.
B) Mercury has a lower viscosity than water.
C) Mercury has a higher boiling point than water.
D) Mercury is more readily available than other liquids.

Answer 1

Mercury is used in a barometer because it has a higher density than water, allowing for a shorter and more compact instrument.

Step-by-step explanation:

A barometer is used to measure air pressure, and the choice of fluid in a barometer is important because it affects the size and accuracy of the instrument.

Mercury is used in a barometer because it has a higher density than water or other liquids. Due to its high density, a barometer filled with mercury can be shorter and more compact than a barometer filled with water.

If water were used, the barometer would need to be over 30 feet tall, which is not practical.

Therefore, the correct answer is A) Mercury has a higher density than water.