Chapter 5 Electrons in Atoms (Glencoe Chemistry Matter and Change)

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 6.626x10^-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 quantum of 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