Unit 1 ch 301

radio waves

• excites the spin of nucleus used in MRI

• responsible for FM, AM radio

Micro waves

• exites spin of electrons

• exites rotation of H20 and fats

Infared

• causes vibration in molecules

• used in night vision goggle

• exites wavelength of OH-

visible

• 300-800nm

• exites valence electrons to higher energy level

• solution for H atom (balmer series)

• rays of detection for human eye

UV

• exites valence electrons

• lyman series for H emission

x-rays

• exites core electrons

• used in medicine for invasive imaging

• causes cell mutations so limit exposure

gamma rays

• associated with decay of atom nuclus

• emitted from stars

• cosmic ray

alkali metals have low ___ ___ and an active __ surface

Ionization Energy… metal

Incoming photons only eject electrons off thes urface if the photon’s energy is greater than the metal’s ___ energy

threshold

according to classical mechanics, intensity of the light should make any hv eject electrons, but

this does not happen

intensity of light

does not effect electrons being ejected

according to planck and einstein, thinking of light as a particle, a photon will

eject electrons with enough energy

photons with energy above the threshold energy will cause

electrons to be ejected with higher velocities

rydberg equation

explains behavior of electrons in an H atom…relates to bohr’s atom, rise and fall of electrons in energy levels

light is a ___ and ____

wave… particle

• diffraction, reflection, polarization

matter is a ____ and _____

wave… particle

E= hv is a ___

photon is postulated

light is

wave-like

matter is a

particle

as matter gets smaller, it

does NOT behave like a particle

de Broglie postulated that matter also acts as a

wave

“light and matter bot have

dual-nature: wave-like and particle-like”

schrodinger developed

quantum mechanics

schrodingers equation explains

the wave behavior of electrons

uncertaintly principle

you cannot know the exact location of an electron, BUT the most probable

• not all locations of an electron are possible

neutrons

neutral fundamental particles, define the kind of isotope of an element

protons

define the kind of element

electrons

negatively charged, do the work of forming chemical bonds between atoms so compounds can exist

ions

when number of electrons is not equal to the number of protons

isotope

when number of neutrons vary

atomic number

number of protons

mass number

sum of protons and neutrons

periods

horizontal rows on table

groups/ families

vertical columns on table

group 1a

• alkali metals

• very reactive in water

• active metals

• form cations

group 2a

alkaline earth metals

group 7a

• halogens (or halides)

• form anions

group 8a

• noble gases

four blocks on periodic table

s, p, d, f (the subshells)

s + p block made up of

main group elements

d block is made up of

transition metals

f block is made up of

• lanthanide series (in 6th period/ top row)

• actinide series (7th period/ bottom row)

shells are

energy levels (n/ principal)

four quantum numbers:

n, l, ml, ms

aufbau principle

electrons fill from lowest to highest energy level

Hunds

spread out electrons when they have the same energy levels in p and d orbitals

Pauli

no two electrons have the same set of quantum numbers (no more than 2 e per orbital & 2 e in same orbital must have opposite spin)