Quantum Orbitals and Electron Configuration

How many subshells are in a d orbital and how many electrons can it hold?

5 subshells, 2 electrons per subshell, for a total of 10 electrons

What are the orbitals in order from the least subshells to most?

s, p, d, f (sexy people do freaky)

Explain why the 3d orbital has slightly higher energy than the 4s orbital.

The 4s orbital fills before 3d due to lower energy at the start, but once filled, 3d is slightly higher in energy than 4s

According to the Aufbau principle, what determines the order in which electrons fill orbitals?

Electrons occupy orbitals starting from the lowest energy level to higher energy levels

Describe Hund’s Rule and how it affects electron placement in orbitals.

One electron must occupy each orbital of the same energy before pairing occurs, minimizing electron repulsion

What is the Pauli Exclusion Principle and how is it represented in orbital box diagrams?

No two electrons in an atom can have the same set of quantum numbers; in diagrams, electrons in the same orbital spin in opposite directions (↑↓)

How would you write the electron configuration for an element with 5 electrons in the 2p orbital using orbital box counting?

2p⁵

How do you write an electron configuration using the noble gas shortcut for bromine?

[Ar]3d¹⁰4s²p⁵

Write the noble gas that comes before the element in square brackets, and write the electron configuration that follows the noble gas until the element.

How do ion charges affect electron configurations?

Electrons are added or removed according to the ion’s charge, modifying the neutral atom’s configuration

Why are half-filled and fully filled orbitals more stable than partially filled orbitals?

Full orbitals yield maximum stability; half-filled orbitals provide partial stability and are more stable than unequal electron distributions

What mistake occurs if you violate Hund’s Rule when filling orbitals?

Placing two electrons in the same orbital before each orbital of the same energy has one electron

When writing electron configurations, why must you start with the lowest energy orbital first?

To satisfy the Aufbau principle and ensure the atom is in its ground state

Which orbitals increase in energy as you move up the columns in an orbital diagram, and what is an exception to this rule?

Orbital energy generally increases with principal quantum number (e.g., 2s < 3p), except 3d is slightly higher than 4s