What is a characteristic of the correct Lewis structure for HCl?

In the Lewis structure for hydrogen chloride (HCl), the important concept is that hydrogen can only accommodate a maximum of two electrons due to its position in the first period of the periodic table. Therefore, rather than adhering to the octet rule—which states that atoms tend to bond in a way that gives them eight electrons in their valence shell—hydrogen is content with just two electrons.

Chlorine, on the other hand, is a second-period element and can follow the octet rule. In HCl, chlorine shares one of its electrons with hydrogen, effectively allowing both atoms to achieve a stable electronic configuration. While chlorine indeed has more than two electrons in the overall structure (it accommodates a full octet), hydrogen's unique behavior means that it doesn't need eight electrons to be stable. This highlights that all atoms except hydrogen can be expected to fulfill the octet rule in a Lewis structure.

Thus, the characteristic that all atoms must have an octet except for hydrogen is essential in accurately depicting the bonding and electron sharing found in HCl.