How can I write the Lewis dot structure for C2H6?

The first step in drawing the for ethane (##C_2H_6##) is to determine how many are available for the molecule.

Since ##C## has 4 , and each ##H## atoms contributes 1 valence electron, the total number of electrons will be

##2*4 + 6*1 = 14## ##"e"^(-)##

This means that the Lewis dot structure for ##C_2H_6## must account for 14 , either through between atoms, or through lone pairs.

So, the two ##C## atoms are placed in the center of the molecule. Each ##C## atom forms three with three ##H## atoms, with one aditional covalent bond being formed between the two ##C## atoms.

Each of these seven single bonds contains 2 electrons, which means that a total of

##7 * 2 = 14## ##"e"^(-)## were used for the ##C_2H_6## molecule.