Sugar = C12 H22 O11

Physicists will tell you that sugar, or sucrose, is an organic molecule composed of carbon (C), hydrogen (H) and oxygen (O). Its chemical formula is C₁₂ H₂₂ O₁₁, with a molar mass of 342.30 g/mol. 

To be more precise, sucrose consists of two molecules, one of fructose and the other of glucose. Experts have given it the official, internationally recognised - and virtually unpronounceable - name of D-glucopyranosyl-D-fructofuranose.