Chapter 4 Key Terms Flashcards
electromagnetic radiation
form of energy consisting of waves and made up of oscillating electric and magnetic fields at right angles to each other
amplitude
height of a wave measured from its origin to its crest
wavelength
distance between successive crests of the wave
frequency
number of waves that pass a certain point in a given amount of time
speed of light (c)
speed at which light waves travel; 3.00 x 10(superscript 8) meters per second (m/s) in a vacuum
visible spectrum
a continuous spectrum containing the array of colors from violet, to indigo, to blue, to green, to yellow, to orange, to red
quantum
word meaning fixed amount (plural = quanta)
Planck’s constant
h in the equation relating energy, E, to the frequency, v, of the radiation that goes as follows: E= hv. It has a value of 6.6261 x 10(superscript-34) Joules per second
photoelectric effect
phenomenon in which light can be used to knock electrons out of a metal; can be explained only in terms of the particle nature of radiant energy
photon
quantum for electromagnetic energy
line spectrum
a spectrum that contains only certain colors, or wavelengths (as opposed to a continuous spectrum)
quantum number
n; a labeling of each energy level, and consequently each orbit, that was given to them by Bohr
ground state
lowest energy level, in which n=1
excited state
a level of higher energy to which an electron can jump if it absorbs the appropriate amount of energy which has a quantum number n=2, n=3, n=4, and so on
matter wave
the wavelike behavior of particles as referred to by De Broglie
uncertainty principle
states that it is impossible to know the position and momentum of particles exactly (the position and the momentum of a moving object cannot simultaneously be measured and known exactly)
quantum-mechanical model (of the atom)
explains the properties of atoms by treating the electron as a wave and by including the idea of quantized energies
electron density
the density of an electron cloud (where the density of a region has a positive relationship to the probability of finding an electron in that region)
orbital
a region in the space around the nucleus of an atom where an electron with a particular energy is likely to be found
principal energy level
one of a limited limited number of energy levels in an atom, designated by the quantum number (n) of that prinicipal energy (i.e. n=1), and whose number of sublevels is determined by that quantum number (i.e. for n=1 there is a single sublevel (s), for n=2 , two sublevels (s and p)
sulevel
a division of a principal energy level in an atom (i.e. sublevels s, p, d, and f)
electron configuration (of an atom)
distribution of electrons among the orbitals of the atom determined by distributing the atom’s electrons among levels, sublevels, and orbitals based on a set of stated principles
orbital diagram
representation of an atom in which arrows in boxes are used to show the electron configuration of an atom
