Chapter 3: The Quantum-Mechanical Model of the Atom Flashcards
absorption spectrum
A plot of the absorption of light of a sample of matter as a function of wavelength.
amplitude
The vertical height of a crest (or depth of a trough) of a wave; a measure of wave intensity.
angular momentum quantum number (l)
An integer that determines the shape of an orbital.
binding energy
The energy with which the electron is bound to the metal.
complementary properties
Properties that exclue one another; that is, the more you know about one, the less you know about the other. For example, the wave nature and particle nature of the electron are complementary.
constructive interference
The interaction of waves from two sources that align with overlapping crests, resulting in a wave of greater amplitude.
de Broglie relation
The observation that the wavelength of a particle is inversely proportional to its momentum λ = h / mv.
destructive interference
The interaction of waves from two sources that are aligned so that the crest of one overlaps the trough of the other, resulting in cancellation.
deterministic
A characteristic of the classical laws of motion, which imply that present circumstances determine future events.
diffraction
The phenomena by which a wave emerging from an aperture spreads out to form a new wave front.
electromagnetic radiation
A form of energy embodied in oscillating electric and magnetic fields.
electromagnetic spectrum
The range of the wavelengths of all possible electromagnetic radiation.
electron spin
A fundamental property of electrons; spin can have a value of ±1/2.
emission spectrum
The range of wavelengths emitted by a particular element; used to identify the element.
frequency (v)
For waves, the number of cycles (or complete wavelengths) that pass through a stationary point in one second.
gamma ray (γ) emission
The form of radioactive decay that occurs when an unstable nucleus emits extremely high-frequency electromagnetic radiation.
Heisenberg’s uncertainty principle
The principle stating that due to the wave-particle duality, it is fundamentally impossible to precisely determine both the position and velocity of a particle at a given moment in time.
indeterminacy
The principle that present circumstances do not necessarily determine future evens in the quantum-mechanical realm.
infrared (IR) radiation
Electromagnetic radiation emitted from warm objects, with wavelengths slightly larger than those of visible light.
interference
The superposition of two or more waves overlapping in space, resulting in either an increase in amplitude (constructive interference) or a decrease in amplitude (destructive interference).
magnetic quantum number (ml)
An integer that specifies the orientation of an orbital.
microwave
Electromagnetic radiation with wavelengths slightly lower than those of infrared radiation; used for radar and in microwave ovens.
node
A point where the wave function (
orbital
A probability distribution map, based on the quantum-mechanical model of the atom, used to describe the likely position of an electron in an atom; also an allowed energy state for an electron.
phase
With regard to waves and orbitals, the sign of the amplitude of the wave, which can be positive or negative.
photoelectric effect
The observation that many metals emit electrons when light falls upon the metal.
photon (quantum)
The smallest possible packet of electromagnetic radiation with an energy equal to *hv. *
principal level (shell)
The group of orbitals with the same value of n.
principal quantum number (n)
The integer that specifies the overall size and energy of an orbital. The higher the quantum number n, the greater the average distance between the elctron and the nucleus and the higher its energy.
probability density
The probability (per unit volume) of finding the electron at a point in space as expressed by a three-dimensional plot of the wave function squared (
quantum number
One of four interrelated numbers that determine the shape and energy of orbitals, as specified by a solution of the Schrodinger equation.
quantum-mechanical model
A model that explains the behavior of absolutely small particles such as electrons and photons.
radial distribution function
A mathematical function that represents the total probability of finding the electron within a thin sperical shell at a distance r from the nucleus in an atom.
radio wave
The form of electromagnetic radiation with the longest wavelengths and smallest energy.
spin quantum number (ms)
The fourth quantum number, which denotes the electron’s spin as either 1/2 (up arrow) or -1/2 (down arrow).
sublevel (subshell)
Those orbitals in the same principal level with the same value of n and l.
ultraviolet (UV) radiation
Electromagnetic radiation with slightly smaller wavelengths than visible light.
visible light
Electromagnetic radiation with frequencies that can be detected by the human eye.
wave function
(
wavelength (λ)
The distance between adjacent crests of a wave.
X-ray
Electromagnetic radiation with wavelenghts slightly longer than those of gamma rays; used to image bones and internal organs.
