# How many hydrogen atoms are represented in the formula (CH_3)_2CH_2?

You have ${\left({H}_{3} C\right)}_{2} C {H}_{2}$; I could equally as correctly represent this as ${H}_{3} C - C {H}_{2} - C {H}_{3}$. Is this clear from the formula? I could condense the formula to give ${C}_{3} {H}_{8}$, i.e. 8 hydrogens as required.
So you have got propane, what about butane, ${H}_{3} C {\left(C {H}_{2}\right)}_{2} C {H}_{3}$, what about pentane, ${H}_{3} C {\left(C {H}_{2}\right)}_{3} C {H}_{3}$, what about hexane, ${H}_{3} C {\left(C {H}_{2}\right)}_{4} C {H}_{3}$? How many carbons in each molecule? And how many hydrogens? As the chain grows, of course, the opportunity for isomerism becomes greater. The general formula for alkanes is ${C}_{n} {H}_{2 n + 2}$. Do all the linear alkanes here obey this formula?