chapter 2.4

• organic molecules: a molecule containing carbon atoms
• a carbon atom behaves as if it has four unpaired electrons, this happens because one of the electrons in the outermost spherical orbital moves into the empty dumbbell shaped orbital
• carbon based molecules are structurally and functionally diverse
• carbon atoms can link with other carbon atoms through covalent bonds
• ethane forms when 2 carbon atoms become connected by a covalent bond
• the number of single bonds between two carbons is called the degree of unsaturation
• in ethane there is only one double bond so its degree of unsaturation is 1
• unsaturated hydrocarbons have double or triple bonds
• 2 adjacent carbon atoms can also share 2 pairs of electrons forming a double bond
• a double bond is shorter than a single bond and is not free to rotate, all of the covalent bonds are formed by carbon atoms connected by double bonds
• isomers: molecules with the same molecular formula but different structural formulae