Answer:
The temperature must be changed to 4 times of the initial temperature so as to keep the pressure and the volume the same.
Explanation:
Pressure in the container is P and volume is V.
Temperature of the helium gas molecules =
Molecules helium gas = x
Moles of helium has = 
PV = nRT (Ideal gas equation)
...[1]
After removal of helium gas only a fourth of the gas molecules remains and pressure in the container and volume should remain same.
Molecules of helium left after removal = 
Moles of helium has left after removal = 
...[2]
The temperature must be changed to 4 times of the initial temperature so as to keep the pressure and the volume the same.
No because it changes its composition to ozone
Water, lower, and I'm not too sure for the third one... sorry.
Answer:
The 2s orbital is at a higher energy level.
Explanation:
1s and 2s are the sub-orbitals that are located in an atom. They are nearest to the nucleus and are found on the s sub-orbital. The difference between 1s and 2s is the difference in their level of energy. 1s has low energy as compared to 2s. 1s orbital has the lowest energy because it is located closed to the nucleus. 2s orbital has higher energy than 1s because it's orbit is larger than 1s.
Answer: high pressure because it's stable
Explanation:
Air mass is volume of air which has stable temperature, humidity and pressure horizontally. Over time, each air mass acquires properties of the region by residing over same part of a surface.
Areas of low pressure and high pressure occur where there is warm air and cold air respectively. An air mass usually forms over an area of high pressure. Warm air rises up and cold air takes its place. Warm air has low density and low pressure where as cold air has high density and pressure and therefore, sinks to the bottom. This is a stable condition. The movement of air mass is responsible for maintenance of temperature conditions on Earth.
