Organic compounds are based on hydrocarbons. Hydrocarbons are compounds composed of only hydrogen and carbon. Chains of carbons are linked by carbon-carbon bonds. They make up the back bone of the hydrocarbons. All the other bonding sites on the carbon are filled by hydrogen. This PowerPoint presentation describes the three main families of aliphatic hydrocarbons. Saturation, homologous series, alkane, alkene, and alkyne are defined. Worksheets on this topic are available free of charge on my website at www.evanschemistrycorner.com.