Unit 4 Chemistry

The Atom

the quantum mechanical model grew out of

the study of light

the amount of energy that light possesses depends on its (v) and its (^)

frequency (v) wavelength (^)

the wavelength and frequency of light are ______ proportional to each other and when multiplied equal _______

inversely, the speed of light

c = ^v

the equation for the speed of light

the energy of light is _____ proportional to frequency and _______ proportional to wavelength using E=hv

directly, inversely

electromagnetic spectrum

different forms of light have different energy based on their wavelength and frequency

spectroscope

break up light into its wavelengths. Different wavelengths have different energies.

white light

has a continuous spectrum.

red light

has longer wavelengths and thus less energy than violet light

“bright line” spectrum

not continuous, emitted by a tube of glowing hydrogen

“excited state” of electrons

when electrons absorb a quantum of energy, they become “excited” and move to a higher energy level.

“ground state”

when electrons release energy and move back down to their lowest energy level or “ground state”. The released energy was in the form of a specific wavelength of visible light.

Electrons move to lower energy levels by

emitting light

light emitted from atoms is made up of only certain specific

wavelengths of light. each atom has its own spectrum.

_____ has the most energy and ______ has the least energy

violet, red

aufbau principle

electrons fill the lowest energy level first. “Lazy tenant” rule. As above: 1s,2s,3s,3p…

pauli exclusion principle

each orbital can hold two electrons with opposite spins represented by up and down arrows

hund’s rule

within a sublevel place one electron per orbital before pairing (empty bus seat rule)

electrons interact with the nucleus to make the _______ _________ arrangement possible. This is usually the lowest energy possible.

most stable

the ground state

the lowest energy possible for an atom, aka the most stable arrangement