In response to Boyle’s Law, the pressure of a gas increases as the volume decreases because

the gas particles strike the walls of the container more often

the temperature of the gas increases

the gas particles get bigger

the gas particles strike the walls of the container with more force

the gas particles strike the walls of the container more often

Explanation:

Following Boyle's law, if the amount of gas and the temperature remain constant, the product of the pressure for the volume remains constant, but when altering any of these conditions this value changes and is expressed through the equation:

So, when the volume decreases, the distance that the particles have to travel is smaller and therefore more collisions between particles and between the walls occur per unit of time, that is, the system pressure increases.

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.