College Chemistry Unit 5

Electromagnetic Spectrum

All of the frequencies or wavelengths of electromagnetic radiation

wavelength

Horizontal distance between the crests or between the troughs of two adjacent waves

frequency

the number of complete wavelengths that pass a point in a given time

quantum

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

Planck

Energy comes in packets called quanta

photoelectric effect

The emission of electrons from a metal when light shines on the metal

photons

A quantum, or discrete quantity, of light energy that behaves as if it were a particle.

continuous spectrum

the emission of a continuous range of frequencies of electromagnetic radiation

line spectrum

a spectrum that contains radiation at only certain specific wavelengths

principal quantum number

symbolized by n, indicates the main energy level occupied by the electron

Bohr

planetary model of the atom

ground state

the lowest possible energy of an atom

excited state

A state in which an atom has a higher potential energy than it has in its ground state

einstein

credited for the photoelectric effect

de broglie

Scientist who suggested that all moving particles had a wave motion associated with them

matter waves

wave characteristics of material particles

momentum

mass x velocity

uncertainty principle

it is impossible to know variables precisely in the quantum world (mass and velocity)

heisenberg

uncertainty principle

wavelength formula

speed of light = wavelength x frequency

photon of energy formula

energy = Planck's constant x frequency

De Broglie's formula

wavelength = planck's constant divided by mass x velocity

Heisenberg's formula

position x momentum equals planck's constant divided by 4 x Pi

Dual Nature of light

Light can behave as a wave if as a particle