Helium, oxygen, and hydrogen.
There are in fact 5 gasses you can choose from that are in Mercury's atmosphere. Oxygen, sodium, helium, potassium, and hydrogen.
helium,oxgyen,sodium
mercury has helium hydrogen and potassium
No. Not all planets have gasses. (Mercury doesn't!)
Mercury's weak gravity and close proximity to the hot sun make it easy for gasses to escape.
a very thin amount of vaporized metal
Very, very little, as Mercury's atmosphere is almost a vacuum only minute traces of gasses are found.
Mercury has no atmosphere, however, there is a trace exosphere containing hydrogen, helium, and oxygen, that gets dynamically created and destroyed.
The 3 important gasses (there are more) are:-NitrogenOxygenCarbon Dioxide
The 3 important gasses (there are more) are:-NitrogenOxygenCarbon Dioxide
Mercury is an element, so it can only be broken down further into subatomic particles (proton, electron and neutron).
oxygen, sodium, hydrogen, helium, potassium, argon, carbon dioxide, nitrogen, xenon, krypton, and neon are all gasses on mercury but I can't quite tell you which ones are minor or major.