Chemistry Matter and Change – Glencoe – Chapter 5

electomagnetic radiation
form of energy that exhibits wavelike behavior as it travels through space such as light

wavelength
shortest distance between equivalent points on a continuous wave

frequency
the number of waves that pass a given point per second

amplitude
the wave’s height from the origin to a crest or trough

electromagnectic spectrum
includes all forms of electromagnetic radiation, with the only differences in the types of radiation being their frequencies and wavelengths

quantum
minimum amount of energy that can be gained or lost by an atom

Planck’s constant
value of 6.626×10^-34J*s, where j is the symbol fo rjoule, the SI unit of energy

photoelectric effect
electrons are emitted from a metal’s surface when light of a certain frequency, or higher than a certain frquency, shines on the surface

photon
a massless particle that carries a quantumof energy

atomic emission spectrum
the set of frequencies of the electromagnetic waves emitted by atoms of the element

ground state
the lowest allowable energy state of an atom

quantum number
the number assigned to each orbit

de Broglie equation
predicts that all moving particles have wave characteristics

Heisenberg uncertainty principle
states that it is fundamentally impossible to know precisely both the velocity and position of a particle at the same time

quantum mechanical model of the atom
the atomic model in which electrons are treated as waves

principal quantum number
indicates the relative size and energy of atomic orbitals

principle energy level
major energy level

energy sublevel
pricipal energy level

atomic orbital
wave function predicts a three-dimensional region around the nucleus

electron configuration
the arrangement of electrons in an atom

aufbau principle
states that each electron occupies the lowest energy orbital available

Pauli exclusion principle
states that a maximum of two electrons can occupy a single atomic orbital but only if the electrons have opposite spins

Hund’s rule
states the single electrons with the same spin must occupy each equal-energy orbital before additional electrons with opposite spins can occupy the same orbitals

valence electron
are defined as electrons in the atom’s outermost orbitals – generally those orbitals associated with the atom’s highest principal energy level

electron-dot structure
consists of the element’s symbol, which represents the atomic nucleus and inner-level electrons, surrounded by dots represnenting all of the atom’s valence electrons