Chapter 4A Chemistry Practice Test: Waves, Atomic Models, Spectroscopy, and Quantum Mechanics

Vocabulary practice flashcards covering wave anatomy, historical atomic models, spectroscopy phenomena, and quantum mechanics fundamentals from the Chapter 4A Chemistry Practice Test.

Crest

The highest peak or point of maximum positive displacement on a wave.

Trough

The lowest point or valley of maximum negative displacement on a wave.

Amplitude

The height of a wave measured from its central rest (equilibrium) line to its crest or trough, indicating the wave's intensity.

Wavelength ($\lambda$)

The distance between consecutive corresponding points of a wave, such as from one crest to the next crest.

Relationship between Wavelength and Frequency

An inverse relationship; as wavelength ($\lambda$) increases, frequency ($f$) decreases according to the equation $c = \lambda f$.

Relationship between Frequency and Energy

A direct relationship expressed by the equation $E = hf$ (or $E = h\nu$), meaning higher frequency photons carry higher energy.

Planck's Constant ($h$)

The fundamental constant connecting a photon's energy to its frequency, equal to $6.626 \times 10^{-34}\,\text{J}\cdot\text{s}$.

Violet Light

The visible spectrum color that possesses the shortest wavelength, highest frequency, and highest energy per photon.

Billiard Ball Model

John Dalton's early atomic model that visualizes the atom as a solid, uniform, indivisible sphere.

Cathode Ray Tube Experiment

The experiment conducted by J.J. Thomson that revealed the existence of negatively charged particles, leading to the discovery of the electron as the first known subatomic particle.

Plum Pudding Model

J.J. Thomson's atomic model representing the atom as a diffuse sphere of positive charge embedded with negatively charged electrons like plums in a pudding.

Gold Foil Experiment

Ernest Rutherford's experiment firing alpha particles at thin gold foil, which revealed that atoms possess a dense, positively charged nucleus surrounded mostly by empty space.

Planetary (Bohr) Model

Niels Bohr's atomic model based on elemental emission spectra, portraying electrons traveling in fixed, circular orbits around the central nucleus at definite energy levels.

Heisenberg Uncertainty Principle

A fundamental principle of quantum mechanics stating that it is impossible to simultaneously determine both the exact position and momentum of an electron.

Quantum Mechanical (Cloud) Model

Erwin Schrödinger's model of the atom based on mathematical wave equations that describes regions of high probability (orbitals or electron clouds) where electrons are likely to be located.

prism

An optical instrument designed to separate incoming light into its component colors or individual wavelengths.

Continuous Spectrum

An unbroken spectrum showing all continuous wavelengths of visible light without gaps, produced by white light sources like the Sun or incandescent lamps.

Bright-Line (Emission) Spectrum

A discrete set of distinct, colored lines emitted at specific wavelengths when excited atomic electrons return to lower energy states.

Electric Pickle Demonstration

because pickles are 'pickled' in salt water, the electricity excited the electrons in the sodium of salt; when the electrons returned to their ground state, they emitted the characteristic color of sodium - yellow orange. 

Wave-Particle Duality

The quantum mechanical principle stating that light and subatomic particles (such as electrons) exhibit properties of both waves and localized particles.

Ground State

The lowest, most stable energy level configuration that an atom's electron can occupy.

Excited State

A temporary, higher energy state entered by an electron after it absorbs a specific quantum of energy.

Quarks

Fundamental subatomic particles that combine in specific configurations to make up composite hadrons like protons and neutrons.

Higgs Field and Higgs Boson

A pervasive quantum field and its associated fundamental boson that interact with other particles to endow them with inertial mass.

Large Hadron Collider (LHC)

The world's largest high-energy particle accelerator, located underground at CERN on the border between France and Switzerland.

FermiLab

A prominent United States national particle physics laboratory and accelerator complex located in Batavia, Illinois.