Structural Representations

You will see a variety of chemical structural representations in organic chemistry and on OpenOChem Learn.  For example, the following are some possible representations for ethanol (CH3CH2OH).  Ethanol has the empirical formula C2H6O.  The empirical formula tells us nothing about the structure or connectivity other than the types and amounts of each type of element in the compound.  There are many ways to represent structures in organic chemistry and you need to be able to read them fluently like when you read words.

Condensed Structural Formula

Explicitly shows all atoms, the number of each atom, and connectivity.

 CH3CH2OH

Condensed Structural Formula with bonds

Explicitly shows all atoms, the number of each atom, and connectivity, but with bonds between C atoms.

Kekule Structures

Similar to Lewis structures except the two-electron bonds are replaced with a line.

Line Bond Structures (Bond-line structure, bond-line formula, skeletal structure, skeletal formula)

Implied carbon (C) atoms and Hydrogen (H) on carbons.  Note:  Hydrogens are shown on heteroatoms only (e.g. O, N, P, S, B).