Atomic Structure, Waves, and Electron Configurations

Vocabulary practice flashcards covering wave mechanics, the electromagnetic spectrum, the Bohr and Quantum models of the atom, and electron placement rules.

Energy Level

A specific electron orbit around the nucleus of an atom; an electron must gain energy to move to a higher energy level.

Atomic Emission Spectrum

A specific pattern of colored lines seen when light emitted from a sample of identical superheated atoms is viewed through a prism; used to identify unknown elements in a mixture.

Wavelength ($\lambda$)

The distance between adjacent peaks (crest to crest) of a wave, measured in meters ($\text{m}$).

Frequency ($f$)

The number of wavelengths or complete waves that pass a specified point in one second, measured in hertz ($\text{Hz}$) or reciprocal seconds ($\text{s}^{-1}$).

Speed of Light ($c$)

The constant speed at which all electromagnetic waves travel through a vacuum, equal to $3.00 \times 10^8\,\text{m/s}$.

Planck's Constant ($h$)

A fundamental constant equal to $6.63 \times 10^{-34}\,\text{J}\cdot\text{s}$, used in the equation $E = hf$ to relate the energy of a photon to its frequency.

Crest (Peak)

The highest point or position of maximum upward displacement on a transverse wave.

Trough

The lowest point or position of maximum downward displacement on a transverse wave.

Amplitude

The vertical distance from the wave's rest position to a crest or trough, directly relating to the wave's energy.

Rest Position

The undisturbed equilibrium line of a wave from which crests and troughs are measured.

Electromagnetic Spectrum

The complete range of electromagnetic radiation arranged by frequency and wavelength, extending from gamma rays (highest energy, shortest wavelength) to radio waves (lowest energy, longest wavelength).

Bohr Model of the Atom

An atomic model proposing that electrons travel along defined, circular paths or orbits with specific energies around the nucleus, allowing exact positions and speeds to be calculated.

Quantum Model of the Atom

The modern atomic model stating that electrons occupy three-dimensional probability clouds called orbitals rather than fixed paths, meaning their exact position cannot be precisely determined.

s Orbital

A spherical atomic orbital consisting of $1$ suborbital that can hold a maximum of $2$ electrons.

p Orbital

A dumbbell-shaped (peanut-shaped) atomic orbital set beginning in energy level $2$, containing $3$ suborbitals that hold a maximum of $6$ electrons.

d Orbital

A cloverleaf-shaped atomic orbital set beginning in energy level $3$, containing $5$ suborbitals that hold a maximum of $10$ electrons.

Electron Configuration

A notation summarizing the total number of electrons in each subshell using numbers and letters (analogous to a summary list of housing addresses).

Orbital Diagram (Orbital Notation)

A graphical representation showing individual orbitals as boxes and the spin of each electron as arrows pointing up or down (analogous to a detailed floor plan).

Aufbau Principle

The rule stating that electrons must occupy the lowest-energy orbitals available first before filling higher-energy orbitals ($1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, \dots$).

Pauli Exclusion Principle

The rule stating that an orbital can hold a maximum of $2$ electrons, and they must have opposite spins (represented by one arrow pointing up and one arrow pointing down).

Hund's Rule

The rule stating that when filling orbitals of equal energy (such as the three $2p$ suborbitals), one electron must be placed in each suborbital with parallel spins before any suborbital is paired.

Noble Gas Configuration

A shorthand notation method where the noble gas in the row above the element is written in brackets ($[\text{Noble Gas}]$) to represent core electrons, followed by the remaining valence configuration.

f Orbital

A complex-shaped atomic orbital set beginning in energy level $4$, containing $7$ suborbitals that can hold a maximum of $14$ electrons.

Sublevels in Principal Energy Levels 1 through 4

Principal energy level $1$ contains $s$; level $2$ contains $s$ and $p$; level $3$ contains $s, p,$ and $d$; level $4$ contains $s, p, d,$ and $f$.

Bohr Model vs. Quantum Model: Electron Path and Shape

In the Bohr model, electrons travel along fixed circular orbits. In the quantum model, electrons occupy three-dimensional probability regions (orbitals) with varied shapes including spherical, dumbbell, cloverleaf, and complex.

Energy Level Trends Relative to Nuclear Distance

Energy levels closest to the nucleus possess the lowest energy, while levels farther away possess higher energy; electrons must gain energy to move outward away from the nucleus to higher energy levels.