Electron Configurations and Valence Electrons

This video tutorial covers electron configuration, focusing on how to write orbital diagrams and use noble gas notation. It begins with sulfur as an example, explaining atomic and mass numbers, and progresses to drawing orbital diagrams using Hund's rule. The tutorial also covers electron configurations for ions, such as sulfide and nitride, and discusses valence and core electrons. Transition metals like cobalt, chromium, and copper are explored, highlighting exceptions in electron configurations.

What is the ground state electron configuration for sulfur?

• 1s2 2s2 2p6 3s2 3p6

• 1s2 2s2 2p6 3s2 3p4

• 1s2 2s2 2p6 3s2 3d4

• 1s2 2s2 2p4 3s2 3p4

How many electrons does the sulfide ion have?

• 20

• 18

• 16

• 14

What is the electron configuration for the nitride ion?

• 1s2 2s2 2p3

• 1s2 2s2 2p6

• 1s2 2s2 2p4

• 1s2 2s2 2p5

Which of the following is true about paramagnetic substances?

• They have no unpaired electrons.

• They are weakly repelled by a magnetic field.

• They contain unpaired electrons and are attracted to a magnetic field.

• They have a full outer shell of electrons.

How many valence electrons does nitrogen have?

• 3

• 5

• 7

• 2

What is the electron configuration for the aluminum cation (Al3+)?

• 1s2 2s2 2p5

• 1s2 2s2 2p6

• 1s2 2s2 2p6 3s2

• 1s2 2s2 2p6 3s1

Which noble gas is used in the noble gas notation for aluminum?

• Neon

• Helium

• Argon

• Krypton

What is the electron configuration for cobalt using noble gas notation?

• [Kr] 4s2 3d7

• [Ar] 3d9

• [Ne] 3s2 3p6 4s2 3d7

• [Ar] 4s2 3d7

Which element is an exception to the typical electron configuration rules?

• Sulfur

• Aluminum

• Chromium

• Nitrogen

How many unpaired electrons does chromium have in its ground state?

• 3

• 4

• 5

• 6