Electron Configuration Quiz

Electron Configuration

• Electron configuration describes the arrangement of electrons in an atom.
• Key terms: electron configuration, aufbau principle, Pauli exclusion principle, Hund's rule, valence electron, electron-dot structure.

New Vocabulary

• Electron configuration: Arrangement of electrons in an atom's orbitals.
• Aufbau principle: Electrons fill orbitals with the lowest energy levels first.
• Pauli exclusion principle: A maximum of two electrons can occupy a single orbital, but only if they have opposite spins.
• Hund's rule: Single electrons fill orbitals of the same energy level before pairing up.
• Valence electron: An electron in the outermost shell of an atom.
• Electron-dot structure: A representation of valence electrons using dots around the atomic symbol.

Ground-State Electron Configuration

• The arrangement of electrons in an atom's lowest energy state.
• An example is chlorine, Cl's electron configuration.

The Aufbau Principle

• Electrons occupy the lowest energy orbitals first.
• The order of filling orbitals is shown in an orbital filling sequence diagram.

The Aufbau Principle - Orbital Filling Sequence

• Shows the order in which orbitals fill with electrons, following the principle of lowest energy first.

The Aufbau Principle - Determined Sequence

• The first step in determining an element's ground-state electron configuration is to learn the sequence of atomic orbitals, starting from the lowest energy level and increasing to the highest energy level.

The Pauli Exclusion Principle

• Each orbital can hold a maximum of two electrons, but only if they have opposite spins.

The Pauli Exclusion Principle - Further Explanation

• Every electron has an associated spin, similar to a spinning top.
• An electron can spin in only one of two directions.
• The exclusion principle demands that orbitals filled with paired electrons need to have opposite spins.

Hund's Rule

• Single electrons with the same spin must occupy each equal-energy orbital before additional electrons with opposite spins can occupy the same orbital.

Representing Electrons in Orbitals

• Electrons can be represented by arrows in boxes.
• An arrow pointing up represents an electron spinning in one direction.
• An arrow pointing down represents an electron spinning in the opposite direction.
• An empty box represents an unoccupied orbital.
• A box with a single up arrow represents an orbital with one electron.
• A box with both up and down arrows represents a filled orbital with a pair of electrons with opposite spins.

Orbital Capacity

• s sublevel: Holds 2 electrons.
• p sublevel: Holds 6 electrons.
• d sublevel: Holds 10 electrons.
• f sublevel: Holds 14 electrons.

Hund's Rule - Orbital Filling

• All orbitals will be singly occupied before any is doubly occupied.

Quantum Numbers Relationships

• Table showing the relationships between quantum numbers and electron configuration.
• The principal quantum number correlates to the period number.
• Groups IA and IIA electrons correlate to the s sublevel, groups IIIA-VIIIA to the p sublevel etc.

Noble Gas Notation

• A shorthand method for writing electron configurations.
• Start by looking for the noble gas closest to the element in question (without going over).
• Use the noble gas symbol enclosed in brackets, followed by the remaining electron configuration.
• For example, for Gold [Xe]6s²4f¹⁴5d⁹

Electron Filling in Periodic Table

• A visual representation of the order in which atomic orbitals are filled with electrons.

Quiz Question 1

• The aufbau principle states that each electron occupies the lowest available energy orbital.
• It does not say electrons fill the highest energy orbitals first, or that a maximum of two electrons can occupy a single orbital only when they have opposite spins.

Quiz Question 2

• Helium's electron configuration is 1s²

Quiz Question 3

• Valence electrons are generally associated with the atom's highest principal energy level; they determine the chemical properties of the element.

Quiz Question 4

• In the electron configuration of carbon (1s²2s²2p²), there are 0 electrons in the third p orbital.

Test your knowledge on electron configuration and its principles, including the aufbau principle, Pauli exclusion principle, and Hund's rule. This quiz covers key terms and concepts essential for understanding the arrangement of electrons in atoms.