Understanding Exceptions to the Octet Rule

The video discusses exceptions to the octet rule, where atoms do not always have eight valence electrons. It covers examples like hydrogen, boron, and aluminum, which can have fewer than eight electrons, and xenon, which can have more. The video demonstrates drawing Lewis diagrams for aluminum hydride and xenon pentafluoride cation, explaining how to account for valence electrons and form covalent bonds. It also touches on the debate about how atoms in the third period or beyond can handle more than eight valence electrons, possibly using empty d orbitals.

Which element is an exception to the octet rule because it follows the duet rule?

• Xenon

• Aluminum

• Hydrogen

• Boron

How many valence electrons does aluminum have in aluminum hydride?

• Three

• Six

• Four

• Two

In the Lewis diagram for aluminum hydride, which atom is placed at the center?

• Xenon

• Boron

• Aluminum

• Hydrogen

What is the charge of the xenon pentafluoride cation?

• Negative 1

• Positive 1

• Neutral

• Positive 2

How many valence electrons does xenon have in its outer shell?

• Twelve

• Ten

• Eight

• Six

Which element is the most electronegative and is used in xenon pentafluoride?

• Nitrogen

• Chlorine

• Fluorine

• Oxygen

How many covalent bonds are formed in xenon pentafluoride?

• Six

• Five

• Four

• Three

How many valence electrons are allocated to each fluorine atom in xenon pentafluoride?

• Four

• Six

• Eight

• Ten

What is the total number of valence electrons in xenon pentafluoride cation after accounting for the charge?

• 40

• 42

• 46

• 44

What is one proposed reason for elements in the third period or beyond having more than eight valence electrons?

• They have larger atomic radii.

• They form stronger covalent bonds.

• They can use empty d orbitals.

• They have higher electronegativity.