Methane is combustible, neon is not.
Cobustible substances can catch on fire but non-combustible substances are inflammabe
Combustible liquids can easily catch on fire and burn. Non-combustible liquids cannot, at least under a set of defined conditions.
There are some simple requirments for something to be a convenient fuel - it must be abundant, easily collected and transported, cheap and ideally have a high calorific value per unit volume.Actually...
Yes it is combustable!