Properties of an ideal gas are theoretical assumptions to help analyze the basic properties of gases. Identify ALL of the correct properties of ideal gases. * 1.None of the collisions between molecules are elastic.
2.Individual molecules do not have volume.
3.There are no intermolecular forces between molecules.
4.Ideal gas molecules do not move.
5.Molecules do not collide with one another.
6.Molecules only collide with the container and no kinetic energy is lost.
7.Collisions cause the gas to turn to liquid

i believe you are right for all except the 3rd ( look at sqdancefan his answer is much better)

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.

the correct answer is:

a. formation of precipitation