What is shown by the structural formula of a molecule?

Question

anonymous · Answer

What atom is bonded to what other atom.  For example, in this formula:
|dw:1352139382985:dw|
We learn that the middle carbon of this form of C4H10 (butane) is bonded to three other carbon atoms, while in this formula:
|dw:1352139498432:dw|
we learn that another form of butane exists in which the middle carbon is only bonded to two other carbons.

Are these different substances, despite having identical molecular formulas (C4H10)?  Indeed they are.  They have different properties, react chemically differently, and can easily be isolated from each other.  For example, the first, isobutane, boils at -12C, while the second, n-butane, boils at -1C, eleven degrees higher.

anonymous · Answer

Thanks!(: