Understanding Lone Pairs and Octets

The video tutorial explains how to determine the number of lone pairs on atoms in molecular structures. It covers the octet rule, expanded and incomplete octets, and provides a formula for calculating lone pairs. The tutorial includes examples with carbon, boron, and oxygen atoms, and discusses special cases like radicals and resonance structures.

What is the typical number of electrons an atom aims to have in its outer shell?

• Six

• Eight

• Ten

• Twelve

Which of the following elements can have an expanded octet?

• Phosphorus

• Fluorine

• Nitrogen

• Carbon

How many lone pairs does oxygen typically have when it forms two bonds?

• One

• Two

• Three

• Four

What is the formula used to calculate the number of lone pairs on an atom?

• Bonds minus valence electrons

• Formal charge minus valence electrons

• Valence electrons minus formal charge plus bonds

• Valence electrons minus bonds

How many lone pairs does boron have in BH3?

• Zero

• One

• Two

• Three

What is the formal charge of oxygen in water?

• Zero

• Positive two

• Positive one

• Negative one

How many lone pairs are on the nitrogen atom in the azide ion with a negative charge?

• Two

• Zero

• One

• Three

What is a radical in terms of lone pairs and electrons?

• An atom with a positive charge

• An atom with an odd number of electrons

• An atom with no bonds

• An atom with a complete octet

In NO2, what is the formal charge on the nitrogen atom?

• Zero

• Negative one

• Positive two

• Positive one

How many lone pairs does nitrogen have when it has a negative two charge and one bond?

• Six

• Three

• Two

• One