Lecture 16 - Lewis Structures

These flashcards cover key concepts and definitions related to Lewis structures and the rules governing molecular bonding.

What is the Lewis model of bonding primarily concerned with?

The Lewis model of bonding describes a set of rules for writing structures based on pairs of electrons shared between atoms to achieve full valence shells.

What is the first step in drawing Lewis structures for simple molecules?

Count the total number of valence electrons in the molecule.

Why do atoms share bonds according to the octet rule?

Atoms share bonds to achieve a full valence shell, typically containing 8 electrons.

What is the significance of resonance structures in the Lewis model?

Resonance structures represent equivalent bonding scenarios where electrons are delocalized between more than two nuclei.

How is the formal charge calculated in a molecule?

Formal charge = Valence electrons of free atom - Lone pairs of electrons - 1/2 shared electrons.

What is the maximum number of electron pairs allowed around an atom according to the octet rule?

Atoms can have a maximum of 4 electron pairs, totaling 8 electrons.

What do hypercoordinate molecules allow in terms of bonding?

Hypercoordinate molecules allow atoms to bind more than 4 other atoms and exceed the octet rule.

What must be minimized to determine the most likely Lewis structure?

Minimize the formal charges on all atoms.

What do elements in the 3rd and 4th rows sometimes do in terms of bonding?

They may have extra linkages but still formally obey the octet rule.

What happens if a molecule has more than one plausible structure?

All structures are considered resonance structures.