text: what two elements must be present in butane?   butane---   butane, also called n-butane, is the unbranched alkane with four carbon atoms, ch3ch2ch2ch3. butane is also used as a collective term for n-butane together with its only other isomer, isobutane (also called methylpropane), ch(ch3)3.  butanes are highly flammable, colorless, easily liquefied gases. the name butane was derived by back-formation from the name of butyric acid.   start from here it would be better----  http://en.wikipedia.org/wiki/butane  hope this helps