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.
Answer:
fluorine
Explanation:
The element fluorine has 9 protons and 9 electrons.
0.01742919 is the answer because i worked it out
Fire, explosions, acid, fumes-take your pick here.
A medium can be anything that a wave can pass through e.g the medium can be solid objects, air, water, etc.