@stillthere (View Post)

 Essentially what EnganK said, it's all the hydrocarbons gases in one element. Like NBLE is all the nobel gases in one element, it's helium pretty much. 

so is it like methane? 

@namename (View Post)

 Methane is a hydrocarbon, so therefore GAS covers that. The only hydrocarbon GAS doesn't cover is RFRG, which is essentially freon. RFRG is a halocarbon. 

GAS is natural gas; in real life, oil and natural gas resevoirs are often found together and oil and natural gas can sometimes even occupy the same resevoir.  The fact that OIL turns into GAS and vice versa is testament to that.

@NF (View Post)

RFRG is a chlorofluorocarbon, or CFC.  In real life, CFCs were the first non-toxic, non-flammable, and stable refrigerants; invented by Thomas Midgley Jr.  A CFC is essentialy and acidic gas mixed with carbon.  CAUS (and acidic gas) mixing with GAS (which has carbon in it) to make RFGL which can then become RFRG is testament to that.

@MachineMan (View Post)

 That doesn't take away from the fact it's potentially freon, which is a CFC (chlorofluorocarbon) as well.