Why you should write Lewis dot diagram in clockwise or anticlockwise?

Answer 1

If it's a diagram of a single element it doesn't matter whether you write the valence electrons clockwise or counter clockwise. It should be written in one way or the other to illustrate which electrons are paired and which electrons can bond. For example, nitrogen has five valence electrons. We can write it as two paired and one single, but the correct way to write them is as one pair and three unpaired valence electrons. The easiest way to write it correctly the first time every time is to draw one dot at a time. Only put one electron per side, so after the first time going around the element, you should have four dots assuming the element has at least four valence electrons. Then, repeat the process. If the element has 8 valence electrons, then, it should have four pairs of dots around it. If it has six, like oxygen, it should have two pairs and two unpaired dots around it.

However, if the diagram is for bonded elements in a molecule, the orientation of the bonds with relation to valence electrons gives the molecule either a rectus (right handed) or sinister (left handed) orientation which governs how it behaves and interacts in a living system. In terms of chemistry questions, these orientations help identify stereoisomers, enantiomers, and various other isomer types.