Quantum Theory and Electron Configurations

Flashcards covering key concepts related to quantum theory, light behavior, atomic structure, and periodic properties in chemistry.

Quantum Theory

The explanation of the behaviors and properties of very small particles, such as atoms and subatomic particles.

Wavelength (λ)

The distance between any two adjacent identical points in a wave, typically measured in nanometers (nm).

Frequency (ν)

The number of wavelengths that pass a fixed point per second, measured in hertz (Hz).

Diffraction

The bending of waves around obstacles and openings, demonstrating that light behaves as a wave.

Photoelectric Effect

The ejection of electrons from the surface of metals when it is exposed to light of a certain frequency.

Planck's Quantum Theory

Energy is emitted or absorbed in discrete units called quanta or photons; described with the relation E = hν.

Heisenberg Uncertainty Principle

It is impossible to simultaneously know both the position and momentum of a particle with great precision.

Bohr Theory

Postulated that electrons in an atom occupy specific energy levels and can transition between these levels by absorbing or emitting energy.

Orbital Diagram

A visual representation of the distribution of electrons in an atom's orbitals, where the direction of arrows indicates electron spins.

Hund’s Rule

The most stable arrangement of electrons in subshells is the one with the greatest number of parallel spins.

Pauli Exclusion Principle

No two electrons can have the same four quantum numbers; an orbital can hold at most two electrons with opposite spins.

Electron Configuration

The distribution of electrons among the available subshells in an atom.

Valence Electrons

Electrons in the outermost shell of an atom, primarily involved in chemical bonding.

Atomic Radius

The distance from the nucleus of an atom to the outer boundary of its surrounding cloud of electrons.

Ionization Energy

The minimum energy required to remove an electron from an atom in the gas phase.

Electron Affinity (EA)

The energy change when a neutral atom gains an electron, indicating the stability of the resulting anion.