Electron structure

wave

Is a disturbance or vibration that travels through a vacuum and or through matter

Two types of waves

mechanical waves and electromagnetic waves

Characteristics of waves

wavelength, frequency, and amplitude

Wavelength

The distance between two analogous points in adjacent waves

Frequency

Number of wavelengths passing a given point in a second

Amplitude

Height (depth) of a wave

speed equation

wavelength x frequency

Electromagnetic waves

A form of energy that can travel through space

Electromagnetic wave components

Electric field
Magnetic field
(Both components are described by same frequency and wavelength)

Electromagnetic spectrum

the range of all types of electromagnetic radiation which differ in frequency and wave length

light spectrum order

red(4x 10-7), orange, yellow, green, blue, indigo, violet(7x 10-7)

Electromagnetic spectrum order

radio, microwave, infrared, visible, ultraviolet, x-ray, gamma ray

Black body radiation

Is electromagnetic radiation emitted from heated object

Diffraction

Is the ability of a wave to bend around obstacles in its path or pass through openings called slits

Interference

Occurs when two or more waves interact with each other

constructive interference

Two or more waves are in phase and reinforce each other

destructive interference

Two or more waves are out of phase and cancel each other

Classical wave theory

Predicts the intensity of radiation emitted from black body increases to infinity as wavelength goes to zero

maximum wavelength

Increase with temp but eventually drops off and goes to zero

quantized

Chunks or discrete quantities

Planck equation

E=hv
h = 6.626x 10 -34

E=hc/lambda

photoelectric effect

Wavelengths (or frequencies) of light causes electrons to be emitted from a metal surface

Long wavelength radiation

Does not cause the photoelectric effect, no matter how intense

short wavelength radiation

Does scale the photoelectric effect no matter how weak

Kinetic energy of the electrons

Ejected depends on the wavelength of light used not its intensity

binding energy

The energy needed to break up a nucleus into its constituent nucleons.

Photoelectric equation

Ein = Eout
= W + KE

Incident photon equation

hv (incident photon) = KE (ejected electron) + W (work function)

work function

the amount of energy needed to remove an electron from an atom

Photons

particles of light that carry energy directly proportional to light frequency

Photoelectrons

Electrons that are ejected from a materials surface when it absorbs photons of sufficient energy

threshold frequency

the minimum frequency of light required to eject photoelectrons from a materials surface

continuous spectrum

the emission of a continuous range of frequencies of electromagnetic radiation (sunlight)

emission spectrum

The wavelength of light when electrons drop from higher to lower energy levels. Appears as distinct lines of color

Stationary states

Specific stable energy levels in an atom where electrons reside without radiating energy. Energy remains constant

ground state

Lowest energy state

excited state

Any state in which an electron processes energy greater than the ground state

Absorption

Occurs when an electron absorbs a photon to transition from lower level to higher level of energy

traveling wave

A wave that moves through a medium with changes in the locations of crests and troughs

Standing wave

A stationary wave in a medium with fixed points called nodes. Oscillates in place

Nodes

Points of zero amplitude on a standing wave

Standing wave characteristics

Peaks and toughs at same position
Amplitude at the end is fixed always zero
Magnitude of oscillation is different between points
Nodes- no up or down motion

Complimentary properties

Properties that cannot be precisely measured at the same time. Measuring one property with greater accuracy results in creased uncertainty

Heisenberg uncertainty principle

it is impossible to know exactly both the momentum and the position of a particle at the same time. The more accurate one is the less accurate the other is

de Broglie wavelength

the wavelength associated with a moving particle

de Broglie equation

λ = h/mv

Schrodinger equation

provides a mathematical frame work for predicting the behavior and properties of particles at the quantum level

wave function

describes the quantum state of a particle or system and contain information able the particles position, momentum and other properties

atomic orbital

a three-dimensional volume of space inside an atom where an electron is likely to be found

quantum numbers

the properties of orbitals

Numbers to describe atomic orbits

principal n
angular momentum l
magnetic ml

principle number n

integers 1 to +infinity
orbital size, larger orbit larger energy
larger values means greater probability of finding electron density farther from nucleus

angular moment number

0 and n-1 increases by whole numbers
orbital shape
numeric values are assigned letter

numeric assigned values

0 s
1 p
2 d
3 f

magnetic quantum number

-l to 0 to +l
orientation in space
number of allowed ml values gives the number of orbital orientations for a given type of orbit

orbital shell

same n

orbital subshell

same n and l

as distance between nucleus and electrons increase

the attraction between them decreases

Radial probability

represents the probability of finding an electron within a thin spherical shell at a radial distance from the nucleus

as n gets larger

probability of finding an electron farther from the nucleus increases

radial node

occurs when the probability of finding an electron drops to zero as one radiates from the nucleus

number of radial nodes in s orbitals

is equal to n-1

number of radial nodes in any orbit

is n-l-1

orbital lobes

positive or negative sign changes at a node

degenerate

orbitals in the same shell of a hydrogen atom, same energy