Electron Configuration and Periodic Table

What is the Aufbau Principle?

• The principle that electrons fill the lowest energy levels available.

• The principle that electrons occupy higher energy levels first.

• The principle that electrons are added to the outermost shell first.

• The principle that electrons are distributed evenly among all energy levels.

What is the electron configuration for Al?

• 1s² 2s² 2p⁶ 3s² 3p¹

• 1s² 2s² 2p⁶ 3s²

• 1s² 2s² 2p⁶ 3p²

• 1s² 2s² 2p⁶ 3s² 3p⁶

What is the electron configuration for Na?

• 1s² 2s² 2p⁶ 3s¹

• 1s² 2s² 2p⁶ 3s²

• 1s² 2s² 2p⁶ 3p¹

• 1s² 2s² 2p⁶ 4s¹

What do 'Electrons in Boxes' diagrams represent?

• They illustrate the electron configuration of an atom/ion.

• They show the molecular structure of compounds.

• They depict the energy levels of electrons in a molecule.

• They represent the bonding between atoms in a crystal.

What is the electron configuration for O²-?

• 1s² 2s² 2p⁶

• 1s² 2s² 2p⁴

• 1s² 2s² 2p⁵

• 1s² 2s² 2p³

What is the Pauli Exclusion Principle?

• No two electrons in the same atom can have the same set of four quantum numbers.

• Electrons can occupy the same quantum state in an atom.

• Electrons in the same atom must have opposite spins only.

• All electrons in an atom must have the same energy level.

What is the highest energy sub-shell for p-block elements?

• s-sub-shell

• d-sub-shell

• p-sub-shell

• f-sub-shell

What is Hund's Rule?

• Electrons will fill degenerate orbitals singly before pairing up.

• Electrons will pair up in the same orbital before filling others.

• Electrons will occupy the lowest energy orbitals first regardless of pairing.

• Electrons will fill all orbitals in pairs before occupying any singly.

What is the highest energy sub-shell for s-block elements?

• p-sub-shell

• d-sub-shell

• f-sub-shell

• s-sub-shell

What is the electron configuration for Fe?

• 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁴

• 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁵

• 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁶

• 1s² 2s² 2p⁶ 3s² 3p⁶ 4s² 3d⁷