Electron Configuration and Orbital Theory

This video tutorial explains how to write the electron configuration for Krypton (Kr). It begins by identifying the number of electrons in Krypton using the periodic table. Two methods for determining electron configuration are discussed: the diagonal rule and using the periodic table blocks. The video provides a step-by-step guide to filling the electron orbitals, starting from 1s to 4p, and concludes with tips on writing configurations correctly.

What is the atomic number of Krypton, and how does it relate to its electron count?

• Atomic number is 10, which equals the number of electrons.

• Atomic number is 36, which equals the number of electrons.

• Atomic number is 54, which equals the number of electrons.

• Atomic number is 18, which equals the number of electrons.

Which rule can be used to determine the electron configuration by following arrows?

• Periodic Rule

• Orbital Rule

• Electron Rule

• Diagonal Rule

What is the maximum number of electrons that the 's' orbital can hold?

• 8

• 2

• 4

• 6

After filling the 3d orbital, which orbital do we fill next for Krypton?

• 4s

• 4p

• 5s

• 3p

How many electrons can the 'd' orbital hold?

• 12

• 6

• 8

• 10

What is the electron configuration notation for Krypton?

• [Ar] 4s2 3d10 4p6

• [Ne] 3s2 3p6 4s2

• [He] 2s2 2p6 3s2

• [Ar] 3d10 4s2 4p6

Which block of the periodic table is filled last in Krypton's electron configuration?

• d block

• p block

• s block

• f block

What is the significance of the 4s orbital in relation to the 3d orbital in electron configuration?

• 4s is filled before 3d

• 3d is filled before 4s

• 4s and 3d are filled simultaneously

• 4s is never filled

Why might the 4s orbital sometimes be written after the 3d orbital in electron configurations?

• It is a historical convention.

• It reflects the order of energy levels.

• It is a stylistic choice.

• It is a mistake in notation.