[SOLVED] why are noble gases, gases? 1. The problem statement, all variables and given/known data this has bothered me for some time, what determines the density of an element at normal atmoshpheric conditions? and more importantly what determines if a substance at s.t.p is a gas solid or liquid 2. Relevant equations gas laws, maybe? 3. The attempt at a solution i was thinking there might be some repulsion and atractions between atoms, like with Ar it contains a full outer shell which means to gain more electrons it would require a new level which would take alot of energy, compared to Sulfur which is trying to complete a full outer shell, which reqiures less energy. so there is more atractration between atoms. this only can aply for some atoms, help?