Chap 7 vocab Flashcards
electromagnetic radiation
Oscillating, perpendicular electric and magnetic fields moving simultaneously through space as waves manifested as visble light, x-rays, microwaves, radio waves ect
Frequency (v)
The number of cycles a waave undergoes per second. rated to s^-1. also Hz
Speed of Light (c)
A fundamental constant giving the speed at which electromagnetic radiation travels in a vacuum
Amplitude
the height of the crest of a wave; related to the intensity of the energy.
electromagnetic spectrum
the continuum of wavelengths of radiant energy.
infrared (IR)
The region of the electromagnetic spectrum between the microwave and visible regions.
Ultraviolet (UV)
Radiation in the region of the electromagnetic spectrum between the visible and x-ray regions
Refraction
A phenomenon in which a wave changes its speed and therefore its direction as it passes through a phase boundary into a different medium
Diffraction
The phenomenon in which a wave striking the edge of an object bends around it.
Quantum Number
A number that specifies a property of an orbital or an electron
Planck’s constant (h)
A proportionality constant relating the energy and frequency of a photon, equal to 6.626x10^-34J(s)
Quantum
A packet of energy equal to hv. The smallest quantity of energy that can be emitted or absorbed
Photoelectric Effect
The observation that when monochromatic light of sufficient frequency shines on a meta, an electric current is produced
Photon
A quantum of electromagnetic radiation
Line spectrum
A series of separated lines of different colors representing photons whose wavelengths are characteristic of an element
stationary state
On of the allowable energy levels of the atom in which it does not release or absorb energy.
ground state
The electron configuration of an atom or ion that is lowest in energy
excited state
Any electron configuration of an atom or molecule other than the lowest energy state
spectrometry
Any instrumental technique that uses a portion of the electromagnetic spectrum to measure the atomic and molecular energy levels of a substance
emission spectrum
The line spectrum produced when excited atoms return to lower energy levels and emit photons characteristic of the element
absorption spectrum
The spectrum produced when atoms absorb specific wavelengths of incoming light and become excited from lower to higher energy levels
de Broglie wavelength
The wavelength of a moving particle obtained from the de Broglie equation
wave-particle duality
The principle stating that both matter and energy have wavelike and particle-like properties
uncertainty principle
the principle stated by Werner Heisenberg that it is impossible to know simultaneously the exact position and velocity of a particle; the principle becomes important only for particles of very small mass