Lewis Structures and Valence Electrons

The video tutorial focuses on exceptions to the octet rule, explaining how some atoms like hydrogen and boron do not follow the rule by having less than 8 electrons. It provides examples of drawing Lewis structures for boron trifluoride (BF3) and sulfur hexafluoride (SF6), illustrating the concept of expanded octets for elements in period 3 or below. The tutorial also covers sulfur tetrafluoride (SF4) and how to handle extra electrons in Lewis structures. The video concludes with a brief introduction to the VSEPR theory, which will be discussed in the next video.

Which of the following atoms is an exception to the octet rule because it can only handle 2 electrons?

• Oxygen

• Carbon

• Hydrogen

• Nitrogen

Boron is often stable with how many electrons?

• 2 electrons

• 8 electrons

• 6 electrons

• 4 electrons

When drawing the Lewis Structure for BF3, how many total valence electrons should be present?

• 18

• 12

• 24

• 30

In the Lewis Structure of BF3, which atom is placed in the center?

• Hydrogen

• Oxygen

• Boron

• Fluorine

Which period on the periodic table allows elements to have an expanded octet?

• Period 1

• Period 4

• Period 2

• Period 3

What is the total number of valence electrons in the Lewis Structure of SF6?

• 54

• 48

• 42

• 36

In the Lewis Structure of SF4, how many valence electrons should be present?

• 38

• 32

• 34

• 36

What should be done if a Lewis Structure is missing electrons?

• Ignore the missing electrons

• Add them to the central atom

• Remove bonds

• Add them to the outer atoms

Why is it acceptable for sulfur to have more than 8 electrons in its Lewis Structure?

• Sulfur is in period 3 or below

• Sulfur is in period 2

• Sulfur is a noble gas

• Sulfur is a metal

What topic will be discussed in the next video following the discussion on Lewis Structures?

• Molecular Orbital Theory

• VSEPR Theory

• Hybridization

• Covalent Bonding