Bob adds heat to a substance. When enough heat is added, A. its particles move closer together and the substance becomes a gas.
B. its particles move farther apart and the substance becomes a solid.
C. its particles move farther apart and the substance becomes a gas.
D. its particles move closer together and the substance becomes a solid.

C. its particles move farther apart and the substance becomes a gas.

Explanation:

A. is wrong because moving closer together creates a solid, not a gas.

B. is wrong because moving father apart creates a gas, not solid.

C. is correct because moving farther apart creates a gas.

D. is wrong because when heat is added particles spread apart because they vibrate faster. Although, in a solid the particles are closer together.

- Just know the states of matter and how the particles move and that will help with this problem.

water is used to store them because it would keep the radiation from getting out in the open and causing harm to the workers

a mercury barometer is a device that uses the physical properties of mercury in a tube to measure barometric pressure. mercury barometers are used for : -

1. measurement of atmospheric pressure  

2. determining the altitude of a place

3. weather forecasting

4. calibration and checking of aneroid barometers

5. application in fluid mechanics

6. measurement of pressure in aircrafts

7. surface weather analysis

8. preparation of barographs

9. usage in physical sciences like physics, astronomy & chemistry

10. preparation of aircraft altimeters

characteristics of mercury barometer : -

1.used to define and measure atmospheric pressure.

2.on the average at sea level the column of mercury rises to a height of about 760 mm.

3.this quantity is equal to 1 atmosphere.

4.it is also known as standard atmospheric pressure.

5.a barometer in which the weight of a column of mercury in a glass tube with a sealed top is balanced against that of the atmosphere pressing on an exposed cistern of mercury at the base of the mercury column, the height of the column varying with atmospheric pressure.