Download 4.2 The Quantum Model of the Atom Vocab Electromagnetic

4.2 The Quantum Model of the Atom
Vocab
Electromagnetic Radiation
- The radiation associated with an electric and magnetic field; it varies periodically and travels at the speed
of light.
Electromagnetic Spectrum
- All of the frequencies or wavelengths of electromagnetic radiation.
Wavelength
- The distance from any point on a wave to an identical point on the next wave.
Frequency
- The number or cycles or vibrations per unit of time; also the number or waves produced in a given amount
of time.
Photoelectric Effect
- The emission of electrons from a material when light of certain frequencies shines on the surface of the
material.
Quantum
- The basic unit of electromagnetic energy; it characterizes the wave properties of electrons.
Photon
- A unit or quantum of light a particle of electromagnetic radiation that has zero rest mass and carries a
quantum of energy.
Ground State
- The lowest energy state of a quantized system.
Excited State
- A state in which an atom has more energy than it does at its ground state.
Emission-Line Spectrum
- A diagram or graph that indicates the degree to which a substance emits radiant energy with respect to
wavelength.
Continuous Spectrum
The uninterrupted broad band of all colors [wavelengths] emitted by incandescent solids.
The Heisenberg Uncertainty Principle
The Heisenberg uncertainty principle states that it is impossible to determine simultaneously both the
position and velocity of an electron or any other particle.
Quantum Theory
Quantum theory describes mathematically the wave properties of electrons and other very small particles.
Orbital
An orbital is a three-dimensional region around the nucleus that indicates the probable location of an
electron.
Quantum Numbers
Quantum numbers specify the properties of atomic orbitals and the properties of electrons in orbitals.
Angular Momentum Quantum Number
The principal quantum number symbolized by n, indicates the main energy level occupied by the electron.
Magnetic Quantum Number
The magnetic quantum number symbolized by m, indicates the orientation of an orbital around the nucleus.
Spin Quantum Number
The spin quantum number has only two possible values [+1/2, -1/2] which indicate the two fundamental
spin states of an electron in an orbital.