chem 301 unit 1 yipeeee

i have been listening to swan lake like crazyyyyy

T tera

10^12

G giga

10^9

M mega

10^6

k kilo

10^3

h hecto

10^2

d deci

10^-1

c centi

10^-2

m milli

10^-3

mew micro

10^-6

n nano

10^-9

p pico

10^-12

electromagnetic radiation

waves of the electromagnetic field which propogate through space and carry momentum and electromagnetic radiant energy

electromagnetic waves

synchronized oscillations of electric and magnetic fields

wavelength (lambda)

distance between two adjacent peaks (throughs)

frequency (nu)

number of wavelengths that pass through a point at each second

c

3× 10^8 m/s

wavelength and frequency equation

lambda = c/nu (wavelength=speed/frequency)

order of waves by increasing wavelength

gxuvimr

good xylophone under viola interest meeting room

gammarays xray ultraviolet visible infrared microwaves radio waves

visible light wavelength range

380-750 nm

visible spectrum

a continuous range of colors with no blank spots ex: the rainbow

light absorption

some substances absorb ultraviolet and/or visible light

unabsorbed light bounce off is the color

absorbance is dependent on

nature of substance

how much substance

thickness

absorbance equation

A= I/I(vo) (absorbance = light passing through/incident light)

beer-bouguer-lamberts law

A= episilon* l * c (absorption= coefficient of absorption * length * concentration)

motion of radio waves on matter

excites spin of nucleus (spin faster)

radio waves use example

MRI, AM, FM radio

motion of microwaves on matter

excites spin of electrons, collisions cause friction, causes heat

microwaves use examples

in the microwave excites rotation of H2O and fats around 12 cm to cook food

motion of infrared on matter

causes vibration in molecules

infrared use examples

night vision googles, heat lamps, excites wavelength of OH in ethanol used to measure intoxication

motion of visible on matter

excites valence electrons to higher energy levels

visible use examples

solution for H-atoms (Balmer series), rays of detection for human eye

motion of ultraviolet on matter

excites valence electrons

ultraviolet use examples

Lyman series for H emission, causes sunburns

motion of x-rays on matter

excites core electrons

xrays use examples

invasive imaging, causes cell mutations

motion of gamma rays on matter

associated with the decay of atom nucleus

gammarays use examples

emitted from stars, radiation

wave model limitations

blackbody radiation

photoelectric effect

emission spectra

blackbody radiation

emission of light from hot objects

photon

radiant energy striking the metal surface behaves like a stream of tiny energy packets

photoelectric effect

emission of electrons from metal surface

emission spectra

emission of light from electronically excited gas atoms

quantum

minimum amount of any physical entity involved in an interaction

here minimum amount of energy is required to produce higher frequency radiation

Plank’s constant

h= 6.626 ×10^-34 J*s

energy equation

E=h*nu (energy= plank’s constant*frequency)

ejecting electrons according to classical mechanic

the intensity of the light should make any hv energy eject electrons, but this does not happen

ejecting electrons according to Planck and EInstein

thinking of light as a particle, a photon, of enough energy 𝐸 = ℎ𝑣 will eject electrons. (ℎ𝑣 is a photon)

photoelectric effect equation

E= E threshhold + KE(ve-) (kinetic energy= work function + kinetic energy ejected e-)

photon with energy above the threshold energy will cause

electrons to be ejected with higher velocities

the larger the “gap” between the threshold and the photon energy,

the higher the electron velocity

black-body radiation

the thermal electromagnetic radiation emitted by a black body

black body

an idealized opaque, non-reflective object,

it has a specific continuous spectrum of wavelengths, inversely related to intensity, that depend only on the body’s temperature

according to the bohr model

electrons orbit the nucleus only at specific, fixed distances called quantized energy levels

no electrons can be found between orbits

as energy levels get closer they become the 1/n² function given by rydberg equation showing

energy level spacings are discrete and not continuous as classical mechanics would predict

Lyman

fall to n=1, uv range photon emission

Balmer

fall to n=2, visible irange photon emission

Paschen

fall to n=3, ir range photon emission

a in rydeberg eq.

(1/n(v0)²-1/n(vb)²)

inversely related to wavelength

de brogile on electrons and wavelengths

an electron moving about the nucleus of an atom behaves like a wave and therefore has a wavelength

wavelength depends on

mass and velocity