Electromagnetic Spectrum and Quantum Theory

Practice vocabulary flashcards covering the electromagnetic spectrum, wave equations, quantum mechanics principles, and atomic electron configurations.

Electromagnetic spectrum

The full range of electromagnetic radiation ordered by frequency/wavelength, all of which travels at $c$ in a vacuum.

EM spectrum order (increasing frequency)

Radio → microwave → infrared → visible (ROYGBV) → ultraviolet → X-ray → gamma.

Gamma rays

Electromagnetic waves that possess the highest penetration power, which increases with frequency.

Speed of light ($c$)

$3 \times 10^8\,m/s$ in a vacuum.

Planck's constant ($h$)

$6.626 \times 10^{-34}\,J \cdot s$.

Wave equation

$c = \lambda \nu$, where $c$ is the speed of light, $\lambda$ is wavelength, and $\nu$ is frequency.

Energy equation

$E = h\nu$, where $E$ is energy, $h$ is Planck's constant, and $\nu$ is frequency.

Atomic emission spectroscopy

A technique where atoms are excited with heat or electricity, causing electrons to jump to higher energy levels and then fall back, emitting light at specific wavelengths.

Atomic emission spectrum

The specific wavelengths of light emitted by an element, serving as a unique fingerprint for that element.

Continuous spectrum

An unbroken rainbow containing all wavelengths of light.

Line spectrum

A spectrum consisting of only specific wavelengths, appearing as thin lines on a dark background.

Photoelectric effect

The phenomenon where light shining on metal knocks out electrons only if its frequency exceeds a threshold frequency, regardless of brightness, causing instant electron emission above that threshold.

Photon

A massless packet of light energy.

Quanta of energy

The smallest discrete amount of energy that can be absorbed or emitted.

Particle-wave duality of light

The principle that light exhibits properties of both waves (such as diffraction and interference) and particles (such as the photoelectric effect).

De Broglie matter waves

The concept that all matter possesses wave properties ($\lambda = \frac{h}{mv}$), with electrons behaving as standing waves around the nucleus so that only specific orbits fit, resulting in quantized energy.

Heisenberg uncertainty principle

A principle stating that it is impossible to know an electron's exact position and momentum simultaneously.

Schrödinger wave equation

A mathematical formulation that describes electrons as wave functions, where the solutions represent orbitals (regions of probability) exhibiting superposition until measured.

Quantum theory

A theory proposing that energy and matter exist in discrete units and display both wave and particle characteristics at the atomic scale.

Principal quantum number ($n$)

The quantum number designating the main energy level and orbital size, taking integer values $n = 1, 2, 3\dots$.

Angular momentum quantum number ($l$)

The quantum number specifying the subshell and orbital shape, with possible integer values from $0$ to $n - 1$ ($0=s$, $1=p$, $2=d$, $3=f$).

Magnetic quantum number ($m_l$)

The quantum number describing the spatial orientation of an orbital, taking integer values from $-l$ to $+l$.

Spin quantum number ($m_s$)

The quantum number representing the spin state of an electron, taking values of $+\frac{1}{2}$ or $-\frac{1}{2}$.

Aufbau principle

The rule specifying that electrons occupy the lowest-energy orbitals first before filling higher ones.

Pauli exclusion principle

The rule stating that no two electrons in an atom can have the identical set of four quantum numbers, limiting each orbital to a maximum of 2 electrons with opposite spins.

Hund's rule

The rule stating that for orbitals of equal energy, one electron enters each orbital with parallel spin before any orbital becomes doubly occupied.

Subshell electron capacities

The maximum number of electrons that can occupy each orbital subshell: $s = 2$, $p = 6$, $d = 10$, and $f = 14$.

Electron configuration of Beryllium ($Be$)

$1s^2\,2s^2$ ($[He]\,2s^2$).

Electron configuration of Neon ($Ne$)

$1s^2\,2s^2\,2p^6$ ($[He]\,2s^2\,2p^6$).

Electron configuration of Magnesium ($Mg$)

$1s^2\,2s^2\,2p^6\,3s^2$ ($[Ne]\,3s^2$).

Electron configuration of Iodine

$1s^2\,2s^2\,2p^6\,3s^2\,3p^6\,4s^2\,3d^{10}\,4p^6\,5s^2\,4d^{10}\,5p^5$ ($[Kr]\,5s^2\,4d^{10}\,5p^5$).

Electron configuration of Hafnium

$1s^2\,2s^2\,2p^6\,3s^2\,3p^6\,4s^2\,3d^{10}\,4p^6\,5s^2\,4d^{10}\,5p^6\,6s^2\,4f^{14}\,5d^2$ ($[Xe]\,6s^2\,4f^{14}\,5d^2$).