Rank the three most common types of radiation in order of increasing penetration power

They would be:

Alpha - these are fast moving helium atoms.

Beta - these are fast moving electrons.

Gamma - these are photons, just like light, except of much higher energy, typically from several keV to several MeV.

what is the volume occupied by 40 grams of argon gas (ar) at standard conditions? what volume, in liters, is occupied by 1.5 x 1023 

i think the answer is terrae but not 100 percent sure. ▓▬▬ §