Natural gas is a naturally occurring hydrocarbon gas mixture consisting primarily of methane (CH\( _4 \)), usually with varying amounts of other higher alkanes, and sometimes a small percentage of non-hydrocarbon gases like carbon dioxide, nitrogen, hydrogen sulfide, or helium.
The major constituent of natural gas is Methane. It typically makes up 70% to 90% of the volume of natural gas.
The other options are incorrect:
Propane (C\( _3 \)H\( _8 \)) and Butane (C\( _4 \)H\( _{10} \)) are also components of natural gas, but they are present in much smaller percentages compared to methane. They are often separated from natural gas for use as liquefied petroleum gas (LPG).
Carbon (C) is an element, and while it is the central atom in methane, propane, and butane, it does not exist as a major constituent in its elemental form in natural gas.
Therefore, the major constituent of natural gas is methane.