The diagram shows a dot-and-cross diagram representing an ammonia molecule, NH3\text{NH}_3NH3.
Which of the following is a major limitation of using this dot-and-cross model to represent the bonding in ammonia?
It does not show the sharing of electron pairs that constitutes the covalent bonds between the atoms.
It fails to represent the presence of the non-bonding valence electrons (the lone pair) on the nitrogen atom.
It uses different symbols (dots and crosses) to represent electrons, which can incorrectly suggest that electrons from nitrogen and hydrogen are fundamentally different.
It incorrectly indicates that the three nitrogen-hydrogen bonds are of different strengths and lengths.