an area of an orbital having zero electron probability
Back
diffraction
Front
the scattering of light from a regular array of points or lines, producing constructive and destructive interference
Back
quantization
Front
the concept that energy can occur only in discrete units called quanta
Back
angular momentum quantum number
Front
(l) distinguishes orbitals of given n having different shapes; can have any integer value from zero to n-1
Back
valence electrons
Front
the electrons in the outermost principal quantum level of an atom
Back
quantum mechanical model
Front
the modern description, primarily mathematical, of the behaviour of electrons in atoms
Back
core electrons
Front
an inner electron in an atim
Back
standing wave
Front
a stationary wave as on a string of a musical instrument; in the wave mechanical model, the electron in the hydrogen atom is considered to be a standing wave
Back
probability distribution
Front
the square of the wave function indicating the probability of finding an electron at a particular point in space
Back
nodal surface
Front
node
Back
Planck's constant
Front
the constant relating the change in energy for a system to the frequency of the electromagnetic radiation absorbed or emitted
Back
wavelength
Front
the distance between two consecutive peaks or troughs in a wave
Back
orbital
Front
a specific wave function for an electron in an atom. The square of this function gives the probability distribution for the electron
Back
diffraction pattern
Front
bright spots and dark areas on a photographic plate
Back
Pauli exclusion principle
Front
in a given atom, no two electrons can have the same set of four quantum numbers
Back
line spectrum
Front
a spectrum showing only certain discrete wavelengths
Back
electron spin quantum number
Front
a quantum number representing one of the two possible values for the electron spin, either +1/2 or -1/2
Back
Heisenberg uncertainty principle
Front
a principle stating that there is a fundamental limitation to how precisely both the position and momentum of a particle can be known at a given time
Back
Aufbau principle
Front
electrons enter orbitals of lowest energy first
Back
dual nature of light
Front
the statement that light exhibits both wave and particulate properties
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subshell
Front
a set of orbitals with a given azimuthal quantum number (l). (7.6)
Back
ground state
Front
the lowest possible energy state of an atom or molecule
Back
quantum model
Front
the electron in a hydrogen atom moves around the nucleus only in certain allowed orbits
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electromagnetic radiation
Front
radiant energy that exhibits wavelike behaviour and travels through space at the speed of light in a vacuum
Back
E = mc2
Front
Einstein's equation proposing that energy has mass
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degenerate orbitals
Front
a group of orbitals with the same energy
Back
quantum numbers
Front
numbers which describe various properties of the orbital
Back
continuous spectrum
Front
a spectrum that exhibits all the wavelengths of visible light
Back
principal quantum number
Front
(n) the quantum number relating to the size and energy of an orbital; it can have any positive integer value
Back
magnetic quantum number
Front
m, the quantum number relating to the orientation of an orbital in space relative to the other orbitals with the same l quantum number. It can have integral values between l and - l , including zero. (7.6)
Back
transition metals
Front
several series of elements in which inner orbitals (d or f) are being filled
Back
frequency
Front
the number of waves (cycles) per second that pass a given point in space
Back
Hund's rule
Front
when electrons occupy orbitals of equal energy, one electron enters each orbital until all orbitals contain one electron with their spins parallel
Back
polyelectronic atoms
Front
an atom with more than one electron
Back
photon
Front
a quantum of electromagnetic radiation
Back
wave function
Front
a function of the coordinates of an electron's position in three-dimensional space that describes the properties of the electron