Understanding Electron Configurations

Define electron configuration.

• The speed of electrons in an atom.

• The arrangement of electrons in an atom's orbitals.

• The mass of an electron in an atom.

• The total number of protons in an atom.

What are valence electrons?

• Valence electrons are the electrons in the outermost shell of an atom that participate in chemical bonding.

• Valence electrons are the electrons that are always in the inner shells of an atom.

• Valence electrons are the electrons that do not participate in any chemical reactions.

• Valence electrons are the protons in the nucleus of an atom.

List the three rules that define electron arrangement in atoms.

• Quantum theory

• Electromagnetic theory

• 1. Aufbau principle 2. Pauli exclusion principle 3. Hund's rule

• Thermodynamics law

What is the order of atomic orbitals from lowest to highest energy?

• 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p,

• 1s, 2s, 3s, 4s, 2p, 3p, 4p, 5s, 6s, 5p, 4d, 3d,

• 2s, 1s, 3p, 2p, 4s, 3s, 5s, 4p, 6s, 5p, 4d, 3d,

• 1s, 2s, 3s, 2p, 4s, 3p, 5s, 4p, 6s, 5p, 4d, 3d,

How does the Pauli exclusion principle apply to electron occupancy?

• Electrons can occupy the same quantum state if they have different energies.

• The Pauli exclusion principle allows two electrons to share the same orbital.

• The Pauli exclusion principle dictates that each electron in an atom must occupy a unique quantum state, preventing any two electrons from having identical quantum numbers.

• Electrons must always have opposite spins to occupy the same orbital.

Illustrate Hund’s rule with an example.

• In fluorine, the 2p electrons are distributed as 2p_x¹ 2p_y¹ 2p_z².

• In oxygen, the 2p electrons are distributed as 2p_x² 2p_y⁰ 2p_z⁰.

• In carbon, the 2p electrons are distributed as 2p_x² 2p_y² 2p_z⁰.

• In nitrogen, the 2p electrons are distributed as 2p_x¹ 2p_y¹ 2p_z¹, illustrating Hund's rule.

Predict the chemical properties of an element based on its electron configuration.

• Chemical properties are solely determined by the atomic mass of the element.

• Chemical properties are predicted based on the total number of electrons in the atom.

• The electron configuration has no impact on the chemical properties of an element.

• Chemical properties are predicted based on the number and arrangement of valence electrons in the electron configuration.

Identify the name, symbol, and valency of an element using its electron configuration notation.

• Name: Silver, Symbol: Ag, Valency: +1

• Name: Aluminum, Symbol: Al, Valency: +3

• Name: Copper, Symbol: Cu, Valency: +1

• Name: Iron, Symbol: Fe, Valency: +2