Mastering Electron Configuration: Key Principles and Exceptions

What principle is used to determine the electron configuration of an atom with multiple electrons?

• Pauli Exclusion Principle

• Hund's Rule

• Heisenberg Uncertainty Principle

• Aufbau Principle

According to the Pauli exclusion principle, how many electrons can each orbital hold?

• 4

• 1

• 2

• 3

What is the electron configuration of Hydrogen?

• 2s1

• 2p1

• 1s1

• 1s2

How is the electron configuration of Helium written?

• 1s1

• 1s2

• 2s2

• 2p2

What is the electron configuration of Lithium?

• 1s22p1

• 1s22s1

• 1s2

• 2s2

Which subshell does Boron start to fill after the 2s orbital?

• 4s

• 3p

• 3s

• 2p

According to Hund's Rule, what must happen before any orbital in a subshell gets two electrons?

• All electrons must have opposite spins

• Every orbital in the subshell gets one electron

• All orbitals must be empty

• The subshell must be half-filled

Which orbital has a lower energy level, 4s or 3d?

• They have the same energy

• It depends on the element

• 3d

• 4s

What is the electron configuration of Chromium?

• 3d44s2

• 3d54s1

• 3d64s0

• 3d34s2

Why do some elements have electron configurations that differ from the expected order?

• Because half-filled or completely filled subshells are more stable

• Due to the Aufbau Principle

• Due to the Pauli exclusion principle

• Because of Hund's Rule