Lewis Structures and Electron Configurations

This video tutorial covers the Lewis model of chemical bonding, explaining Lewis symbols and their use in predicting molecular stability. It details the octet rule, which describes how atoms tend to gain, lose, or share electrons to achieve a noble gas configuration. The tutorial also highlights helium as an exception to the octet rule, forming a duet instead. Examples of Lewis symbols for elements in Period 2 are provided, illustrating how valence electrons are represented. The video concludes with a brief mention of additional exceptions to the octet rule to be discussed in future tutorials.

What is the primary purpose of the Lewis model in chemistry?

• To calculate the mass of atoms

• To measure the temperature of reactions

• To determine the stability and structure of molecules

• To predict the color of molecules

How are valence electrons represented in Lewis symbols?

• As dots around the element symbol

• As arrows pointing to the element

• As lines connecting atoms

• As numbers next to the element symbol

Which element in Period 2 has three valence electrons represented in its Lewis symbol?

• Boron

• Lithium

• Beryllium

• Carbon

Why does carbon have four separate dots in its Lewis symbol?

• Because it has a full outer shell

• Due to hybridization

• Due to its metallic nature

• Because it forms ionic bonds

What is the electron configuration for neon that represents a full octet?

• 1s2 2s2 2p4

• 2s2 2p6

• 3s2 3p6

• 4s2 4p6

What does the octet rule state about atoms and their electrons?

• Atoms prefer to have no electrons

• Atoms aim to have eight valence electrons

• Atoms tend to lose all electrons

• Atoms always gain electrons

Which noble gas configuration is achieved by following the octet rule?

• S1 P1

• S2 P4

• S2 P6

• S3 P3

How is helium an exception to the octet rule?

• It forms a quadruplet

• It has a duet of electrons

• It has no electrons

• It forms a triplet

What is the electron configuration of helium that represents its duet?

• 2p2

• 2s2

• 1s2

• 1s1

In which principal energy level does helium fill its electrons?

• N = 2

• N = 3

• N = 1

• N = 4