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Ch. 5 vocab
Term | Definition |
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amplitude | The height of a wave from the origin to a crest, or from the origin to trough |
atomic emission spectrum | A set of frequencies of electromagnetic waves given off by atoms of an element; consists of a series of fine lines of individual colors |
electromagnetic radiation | .A form of energy exhibiting wavelike behavior as it travels trough space; can be described by wavelength, frequency, amplitude, and speed |
electromagnetic spectrum | Includes all forms of electromagnetic radiation; the types of radiation differ in their frequencies and wavelegths |
frequency | The number of waves that pass given point per second |
photoelectric effect | A phenomenon in which photo electrons are emitted from a metal's surface when light of a certain frequency shines on the surface |
photon | A particle of electromagnetic radiation with no mass that carries a quantum of energy |
Planck's constant | 6.626 X 10 -34 J X s, where J is the symbol for the joule |
quantum | The minimum amount of energy that can be gained or lost by an atom |
wavelength | The shortest distance between equivalent points on a continuous wave; is usually expressed in meters, centimeters, or nanometers |
atomic orbital | A three-dimensional region around the nucleus of an atom that describes an electron's probable location |
de Broglie equation | Predicts that all moving particles have wave characteristics and relates each particle's wavelength to its frequency, its mass, and Planck's constant |
energy sublevel | The energy levels contained within a principal energy level |
ground state | The lowest allowable energy state of an atom |
Heisenberg uncertainty principle | States that it is not possible to know precisely both the velocity and the position of a particle at the same time |
principal energy level | The major energy levels of an atom |
principal quantum number | Assigned by the quantum mechanical model to indicate the relative sizes and and energies of atomic orbitals |
quantum mechanical model of the atom | An atomic model in which electrons are treated as waves; also called the wave mechanical model of the atom |
quantum number | The number assigned to each orbit of an electron |
aufbau principle | States that each electron occupies the lowest energy orbital available |
electron configuration | The arrangement of electrons in an atom, which is prescribed by three rules--the aufbau principle, the Pauli exclusion principle, and Hund's rule |
electron-dot structure | Consists of an element's symbol, representing the atomic nucleus and inner-level electrons, that is surrounded by dots, representing the atom's valence electrons |
Hund's rule | States that single electrons with the same spin must occupy each equal-energy orbital before additional electrons with opposite spins can occupy the same orbitals |
Pauli exclusion principle | States that a maximum of two electrons can occupy a single atomic orbital but only if the electrons have opposite spins |
valence electron | The electrons in an atom's outermost orbitals; determine the chemical properties of an element |