Answer
See the explanation
Work Step by Step
To draw the complete Lewis structure for histidine, where all atoms have a formal charge of zero, we need to follow these steps:
1. Identify the atoms present in the given incomplete Lewis structure: carbon (C), nitrogen (N), hydrogen (H), and oxygen (O).
2. Determine the total number of valence electrons available for the molecule. We can do this by counting the valence electrons for each atom:
- Carbon (C) has 4 valence electrons
- Nitrogen (N) has 5 valence electrons
- Hydrogen (H) has 1 valence electron
- Oxygen (O) has 6 valence electrons
The total number of valence electrons is 4 + 5 + (6 × 1) + (5 × 1) = 24 valence electrons.
3. Arrange the atoms in a way that satisfies the octet rule (except for hydrogen, which only needs 2 electrons). The given incomplete structure provides a good starting point.
4. Draw the complete Lewis structure by adding the necessary bonds and lone pairs to ensure that all atoms have a formal charge of zero.
The complete Lewis structure for histidine, with all atoms having a formal charge of zero, is as follows:
$\begin{array}{c}
\ {H-C-N\\ C-N-H\\ \downarrow \\ H-H\\ H-H-H\\ H-C-H-O-H\\ H-C-H\\ H_{1}} \\
\end{array}$
In this structure, all atoms have a formal charge of zero, and the molecule satisfies the octet rule (except for hydrogen, which only needs 2 electrons).
