Chemistry Chapter 5 - Electrons

electromagnetic radiation

a form of energy that exhibits wavelike behavior as it travels back through space

wavelength

shortest distance between equivalent points n a continuous wave

frequency

number of waves that pass a given point per second

amplitude

a wave's height from the origin to a crest

electromagnetic spectrum

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

photoelectric effect

photoelectrons are emitted from a metal's sirface when light of a ceartin requency, or higer than a ceartin frequency, shine on a surface

photon

massless paticle that cares a quantum of energy

atomi emission spectrum

set of frequincies of the electromagnetic waves emitted by atoms of an element

ground state

lowest allowable energy state of an atom

quantum number

Bohr assigned it for his calucations

de Brogie equation

predicts that all moving particles have wave characteristics

Heisenberg uncertainty principle

it is fundamentally impossible to know precisely both the velocity and the position of the a particle at the same time

quantum mechanical model of an atom

the atomic model in which electrons are treated like waves

atomic orbital

describes electron's probabble location

principal quantum number

indicates the relative size and energy of atomic orbitals

principal energy levels

each major enegy level

enegy sublevels

principal energy levels contain sub levels

electron configuation

arrangement in a atom

aufbau principle

each electron occupies the lowest orbital possible

pauli exclusion principle

a maximum of two electronshy can occupy a single atomic orbital as long as the have opposite spins

hund's rule

single electrons with the same spin must occupy each equal energy orbital before additional electons with opposite spins can occupy the same orbitals

valance electrons

electrons in the atom's outermost principal energy level; generally associated with the atom's highest energy level

electon-dot structure

consists of the element's symbol, surrounded by two dots representing all of the atom's valance electrons