High temperature and low pressure<--Most likely
Low temperature and high pressure<----Less likely.
So the answer to this is Low temperature and high pressure.
All the members of a family of elements have the same number of valence electrons and similar chemical properties. The horizontal rows on the periodic table are called periods.
By using the quantum model of the atom and John Dalton's model you can predict that the methane molecule will most likely be made up of Hydrogen and Carbon.
