absorption spectrum
amount of light absorbed by a compound as a function of the wavelength of light
color
phenomenon of light (such as red, green, or blue) or visual perception that enables someone to differentiate otherwise identical objects
conjugated diene
diene consisting of two double bonds that are separated by one single bond
electromagnetic spectrum
entire range of electromagnetic waves, defined by their energy, wavelengths, and frequencies
energy
capacity to do work
frequency
number of oscillations of a wave that occur in a given period of time, usually a second, measured in hertz (Hz)
highest occupied molecular orbital (HOMO)
highest energy level that is occupied by electrons
lowest unoccupied molecular orbital (LUMO)
lowest energy level that is not occupied by electrons
ozone layer
atmospheric layer at heights of about 20 to 30 miles (32 to 48 kilometers), normally characterized by high ozone (O3) content that blocks most solar ultraviolet radiation from entry into the lower atmosphere
period
amount of time required for one vibrational cycle, equivalent to the inverse of frequency
ultraviolet light
light wave situated beyond the visible spectrum at its violet end and consisting of radiation having a wavelength shorter than wavelengths of visible light and longer than those of X-rays
ultraviolet spectrometer
device that measures ultraviolet (UV) electromagnetic waves
vision
ability to see
wavelength
distance between two identical parts of a wave
Woodward-Fieser rules
set of empirically derived rules that predict the wavelength of the absorption maximum () in an ultraviolet–visible spectrum of a given substance