Quantum and Atoms Study Guide

Vocabulary flashcards based on quantum and atomic concepts.

Aristotle

Believed that force is required to keep an object in motion and that matter is continuous and infinitely divisible.

Newton's First Law

An object in motion stays in motion and an object at rest stays at rest unless acted upon by an unbalanced force.

F=ma

Newton's Second Law; acceleration (a) is inversely proportional to mass (m) and directly proportional to force (F).

Action-Reaction

Newton's Third Law; for every action, there is an equal and opposite reaction.

Galileo

Challenged philosophical views and demonstrated that all objects fall at the same rate (neglecting friction).

Leucippus

Proposed that matter is composed of small indivisible elements.

Democritus

Coined the term 'atomos', meaning indivisible; proposed atomic theory.

Huygens

Proposed that light consists of waves and that small wavelets can produce new wave fronts.

Hauy

The first crystallographer who observed the regular geometric patterns in calcite.

Bragg-Bragg

Developed a formula for determining the wavelengths of x-ray diffraction.

Mendeleev

Created the first periodic table organized by atomic mass and properties.

Moseley

Developed the modern periodic table organized by atomic number and properties.

Proust

Formulated the Law of Definite Proportions; compounds have fixed proportions by mass.

Gay-Lussac

Formulated the law of gas volumes; PV = nRT.

Roentgen

Accidentally discovered x-rays.

Geiger-Marsden Experiment

Confirmed the existence of the atomic nucleus.

Geiger-Nuttal Law

Deals with radioactive decay.

Muller

Co-invented the Geiger counter.

Curie-Curie

Discovered polonium and radium; found that radiation comes from atomic nucleus decay.

Compton Effect

Demonstrated that light scatters when it encounters matter, changing wavelength and frequency.

J.J. Thomson

Used cathode ray tubes to discover the charge to mass ratio of the 'corpuscle' (electron).

Perrin

Showed cathode rays were made of negatively charged corpuscles and determined Avogadro's number.

Stoney

Coined the term 'electron' to replace 'corpuscle'.

Becquerel

The SI unit of radiation; discovered natural radioactivity.

Hertz

Defined the SI unit of frequency (Hz); studied electromagnetic waves.

Fraunhofer

Studied absorption spectra and identified absorption lines of the sun.

Balmer

Derived a formula for calculating wavelengths of light in the visible H spectrum.

Paschen

Derived a formula for calculating wavelengths of light in the infrared H spectrum.

Lyman

Derived a formula for calculating wavelengths of light in the ultraviolet H spectrum.

Rydberg

Formulated the equations for calculating wavelengths of light for hydrogen's entire spectrum.

Wien

Established the inverse relationship between the wavelength of peak emission of a black body and temperature.

Planck

Founder of quantum theory; proposed that energy of an atom is quantized (E = nhv).

Einstein (Photoelectric Effect)

Studied how light, composed of photons, causes electrons to be emitted from metals.

Alpha Particle (α)

Helium nucleus (He-4) with no electrons.

Beta Particle (β)

High energy electron with a negative charge.

Gamma Particle (γ)

High energy particle with no charge or mass, released during nuclear decay.

Avogadro's Number

6.02 imes 10^{23} molecules per mole.

Faraday's Constant

96485 ext{ C/mol}.

Absorption Spectrum

Occurs when an atom absorbs energy and its electron moves to a higher energy state.

Emission Spectrum

Occurs when an electron transitions to a lower energy level, releasing energy as a photon of light.

Half-life

Time it takes for a substance undergoing decay to reduce to half its original quantity.

Thomson Model

Plum pudding model; electrons are scattered throughout the atom.

Rutherford Model

Planetary model; electrons orbit around a dense nucleus.

Bohr Model

Electrons occupy specific quantifiable energy levels in orbit around the nucleus.

Quantum Model

Electrons exist as wave functions in specific orbitals with a 95% probability.

Faraday's Electrolysis Experiment

Determined the charge to mole ratio (I α n).

Michelson-Morley Experiment

Failed to prove the existence of aether; showed null difference in the speed of light.

Rutherford Gold Foil Experiment

Demonstrated that some alpha particles are deflected by the atomic nucleus.

Millikan Oil Drop Experiment

Determined the charge of the electron using the charge-to-mass ratio.

Davisson-Germer Experiment

Confirmed the wave properties of electrons thereby supporting quantum theory.

Dalton's Theory

Compounds react in whole number ratios, implying the law of definite combinations.

De Broglie Hypothesis

Any moving particle or object has an associated wave; established wave mechanics.

Heisenberg Uncertainty Principle

Two variables in a quantum system cannot be known with arbitrary precision.

Schrodinger Equation

Mathematically described the wave behavior of electrons.

Pauli Exclusion Principle

No two electrons can occupy the same quantum state within an orbital.

Rydberg Equation

Used to calculate the wavelengths of light emitted by hydrogen.

Moseley Equation

Establishes the relationship between frequency and x-rays of atoms.

Einstein Photoelectric Equation

KE = hf - φ; energy of electrons emitted from light.

Planck Equation

Describes the energy of photons; E = hf.

Balmer Equation

Used for calculating visible hydrogen spectrum wavelengths.

Bohr Equation

hf or h riangle f = E_1 - E_2.

Wien's Displacement Law

Involves the relationship between the wavelength of peak emission and temperature; ext{m} imes ext{K} = 2.9 imes 10^{-3}.