Energy propagated by energetic and magnetic field that increases and then increases in intensity?

electromagnetic radiation

How is electromagnetic radiation described/

by a wave model

What is the wavelength?

What is it represented by?

What is it usually measured in?

distance between the crests of waves

ƛ

nm

What is the frequency?

What is it represented by?

What is it usually measured in?

cycles per second

Greek letter nu (𝜈)

Hertz (Hz) [s^-1]

Relationship between wavelength and frequency?

wavelength increases

frequency decreases

When does the wavelength get more harmful?

the lower it is the more harmful

What is the velocity?

What is it represented by?

What is it usually measured in?

distance a wave can travel per unit time

v

m/s

What is the speed of light?

c = 3.00 x10^8 m/s

What is the equation for velocity?

v = ƛ𝜈

What is the amplitude?

What is it represented by?

What is it usually measured in?

height of crests, depth of troughs

A?

meters

What is amplitude related to?

intensity

What is the relationship between amplitude and intensity/

Amplitude increase, then Intensity increase

What does intensity depend on?

different colors

What causes a change in amplitude?

change in intensity

What is an example of refraction?

rainbows

What is an example of diffraction?

awarenesses that a flashlight is on

Waves travel at different speeds through different media, the transition causes a change in direction?

refraction

Does matter refract or diffract like energy does?

no

Waves bend around the edges of an object?

diffraction

What is blackbody radiation?

an object emitting light when it is heated

As heat is increased to an object, what happens/

the light changes color

What relation does the blackbody radiation show/

relationship between heat & light intensity/wavelength (ƛ)

Who takes the first steps of quantum theory and what did he say?

max planck

objects emit only certain quantities of energy

What equation did plank come up with?

E = nh𝜈

What does each letter stand for in the equation E = nh𝜈 ?

E = energy of radiation

n = the quantum number (positive integer)

h = planks constant

𝜈 = frequency

What is planks contant?

h = 6.626 x10^-34 J x s

What are four major points of planck reasoning?

- objects emit certain quantities of energy
- energy must be emitted by atoms
- atoms must only have certain quantity of energy available to it
- an atoms energy must be quantized

What does quantized mean/

occurring in fixed quantities

When does an atoms energy change?

when it emits or absorbs a quantum

What is the equation for ΔE ?

ΔE = Δ energy absorbed/emitted

ΔE = Δnh𝜈

What is the formula for the smallest possible change in energy?

ΔE = h𝜈

When monochromic light (single wavelength) of a sufficient frequency strikes a metal plate, a current flows with out a time lag?

the photoelectric effect

With the photoelectric effect, for current to flow what must occur?

sufficient frequency

no time lag

What does the threshold frequency change with?

different metals

What is the minimum frequency of light a current requires called?

threshold frequency

What does the classical model of light associate energy with?

associates energy with amplitude instead of frequency

What is the no time lag?

the current flows the moment the light strikes the metal surface

What did Albert Einstein say about light and energy?

light is quantized into bundles of energy

What are the bundles of energy light is quantized into called?

photons

What happens to photons when energy changes?

a photon is absorbed or emitted

What is the E of a photon?

Who said this?

E (photon) = h𝜈 = ΔE (atom)

Albert Einstein

What is the energy of atoms and photons related to and not related to?

related to frequency

not to amplitude

How can an electron not be ejected from the metal by ?

by storying energy from multiple photons

What is the relationship between wavelength and energy?

wavelength decreases, then

energy increases

Scientists saw unique lines across other sections of the electromagnetic spectrum….Who came up with an equation for it?

Johannes Rydberg

1888

What was Rydberg’s equations?

What elements did it work for?

(1/ƛ) = R(H) [(1/n2a) - (1/n2b)]

only H

In Rydberg’s equation what must n be?

n must be an integer

n(a) < n(b)

What is R(H)?

Rydberg’s constant for H

R(H) = 1.096776 x10^7 m^-1

Who made the Bohr model?

Niels Bohr

1915

What was the Bohr model combined ideas of?

planck, einstein, and rydberg

What is the ΔE ?

E final - E initial

What does the Bohr model perfectly define but nothing else?

Hydrogen

What are the 3 ideas of the Bohr model?

- H only has stationary states: only certain energy levels

Each state associated with a fixed circular electron orbit around nucleus.

Higher energy level = Farther from nucleus - Atom in stationary state = no energy radiated

Atom doesn’t not change energy within orbit. - Electron moving to another orbit / atom changing energy state only occurs by absorbing/emitting a photon

What are the five features of the Bohr model?

- quantum numbers and electron orbit
- ground state
- excited state
- absorption
- emission

The number that describes the state of an atom?

quantum number

Distribution of e- that puts an atom at its lowest energy ?

ground state

Distribution where 1 or more electrons move into a higher state so its not at its lowest energy?

excited state

What does the Bohr model only predict?

the line spectra for only H atom

- b/c its a one electron model

What is another issue with the Bohr model other than only working for H?

electrons do not move in fixed orbitals

What do we still use today from the Bohr model?

idea of discrete energy levels

ground state / excited state terms

energy change is related to absorption/emission of specific photon energies

What is a positive change in energy?

going from lower energy state to higher

an atom is absorbing a photon

What is a negative change in energy?

going from lower energy state to higher

an atom is emitting a photon

What did Bohr do and not have for his model?

fit theory to data

no basis for assumption

had no hypothesis

Who studied fixed motion of a wavelength with a guitar string?

Louis de Broglie

What was the big question that formed from Louis de Broglie’s research?

if energy can behave like particles,

why can matter not behave like a wave

What is the formula for harmonics?

L = n (ƛ/2)

What ideas does de Broglie use to form an equation?

What is the equation?

planck and einstein

ƛ = h / (m x u)

What do these variables mean?

u =

v =

c =

speed of the electron

speed

speed of light

What is one J ?

(1 kg x m^2) / s^2

When will waves diffract around a slit or opening?

if the opening is on a similar scale to the wavelength of the light

Who studied and made conclusion about x rays , wavelength, and crystalline materials?

Clinton Davisson

Lester Germer

1927

What was said about the X-ray and wavelengths studied with crystalline?

x-ray wavelength

space between atoms in certain crystals

electron wavelength

What does this mean ?

x ray ƛ = 10^-10

crystals ƛ = 10^-10

electron ƛ = 7.27 x10^-10

electrons have a wavelength b/c diffracted

What did Davisson and Germer see with the electron?

it made a pattern but not the same as the xray

** it has a wavelength

What is momentum?

product of speed and mass

the smaller the wavelength, the higher the ____and _____

energy

momentum

What is the equation for momentum?

p = h/ƛ

What happens when 2 things collide with different momentums/

they separate with the same momentums

* momentum is conserved

What did Arthur Compton say?

1923

wavelength of light changes when its collided with an electron

Who used theory to explain observation?

Who used observation to explain theory?

Planck, Einstein, and Bohr

Davisson, Germer, and Compton

What exhibits both particle like and wavelike behavior/

matter and energy

Who came up with the theory of relativity?

Albert einstein

1905

What is the theory of relativity?

What is the equation?

matter and energy are alternate forms of the same entity

E=mc^2

Who came up with he uncertainty principle?

Werner Heisenberg

1927

What is the uncertainty principle ?

it is impossible to know with certainty both the location and the speed of an electron

What is the formula for uncertainty?

(ΔX)(mΔu) ≥ (h)/(4𝞹)

Δ = uncertainty (not change)

^^^ eq says minimus amount error

The Quantum Mechanics Atomic Model…

focuses on examining the ______ nature of objects on the atomic scale

describes an atom with specific quantities of _____ that result from allowed frequencies in an ____wave behavior

an electrons position can only be known with a certain probability

wave-like

energy

electron

What did Schrödinger say about electrons and space near the nucleus?

the electrons matter-wave occupies space near the nucleus and is influenced by it

What was Schrödinger equation ?

Erwin Schrödinger

*only need to understand

Ĥψ = Eψ

What is Ĥ?

What is ψ?

What is E?

hamiltonian operator

wave function

total energy of the electron

What does a wavefunction solution to the Schrödinger equation describe?

describes an orbital

Each dependable wavelength with the Schrödinger equation depend on a series of variables called what?

quantum numbers

What are the quantum numbers?

What do they describe?

n

ℓ

mℓ

an atomic orbital

What is the QN n?

What numbers are included?

What does it indicate?

a higher value = a ____ energy level

principle QN

positive integer (1, 2, 3…)

size

higher

What is the QN ℓ?

What numbers are included?

What does it indicate?

angular momentum QN

integer from 0 to (n-1)

shape

What is the QN mℓ?

What numbers are included?

What does it indicate?

magnetic QN

integer from -ℓ to +ℓ

orientation

What do we use to describe energy states and orbitals?

wave function and the QN associated

Describing a atom…

What is the n value?

What is the ℓ value?

What is the mℓ value?

shells

subshells

s: ℓ=0

p: ℓ=1

d: ℓ=2

f: ℓ=3

orbitals

How are QN used to write and stuuufff?

nℓ (subscripted mℓ)

What is the meaning?

ψ

ψ^2

no meaning

the probability density

What does ψ^2 describe?

What can we turn it into?

the physical location that an electron can possibly occupy

a 3D shape

What is the shape of the s orbital?

sphere

bigger n = bigger sphere

nodes (n-1)

What is the shape of the p orbital?

Bean / Bowtie shape

bigger n = bigger sphere

3 p orbitals (x, y, and z)

What is the shape of the d orbital?

butterfly

the fifth looks like a p orbital with a circle in the middle

For the H atom…

___ is the only QN to impact the energy of the orbital

the energy of all four n=___ orbitals are equal

- 2s

- 2p(x)

- 2p(y)

- 2p(z)

*only for H

principle QN

n=2

What can Schrödinger equation reveal?

- difficulties arise when there is ____
- the equation becomes___
- requires sophisticated _____

the total energy of an electron in an atom

more than one electron

unsolvable

approximations

What were the additions to the quantum model?

another quantum number

limit to electrons in an orbital

splitting on energy levels

What was the QN added?

What is that QN?

What numbers are included?

What does it indicate?

ms (s is subscript)

spin quantum number

2 possible: +1/2 , -1/2

the direction of spin

What do all four QN describe together?

the spin and the orbital

Who made the exclusion principle?

What did this person observe to form this principle?

Wolfgang

1925

excited states of helium

What are the two main points of the exclusion principle?

- no 2 electrons can have the same exact 4 QN’s in a single atom
- an atomic orbital can only hold 2 electrons, each with opposite spins

What is electrostatistics?

In H, all orbitals with an equal___ have equal ___

In other atoms, energy is based on what?

various effects of interacting charges cause a splitting of energy levels

n, energy

n and ℓ

What is it called when electrons repulse each other counter acting nuclear charge?

shielding

Is it easier to remove an electron with a more or less shielding?

why?

more

effective nuclear charge (Zeff) is reduced

What is Zeff or effective nuclear charge?

What is nuclear charge?

what charge an atom feels

what charge is actually there

Do higher or lower nuclear charges interact more strongly?

higher

Nuclear charge…

a more positive nucleus creates a stronger attraction to the electron, which does what to the overall energy?

lowers the energy

What are the two kinds of shielding ?

- same energy level electrons

- multiple electrons decrease stability - electrons in inner energy levels

- inner electrons block those in outer levels

What is electrical penetration?

what is it based on?

how close to nucleus

based on orbital shapes and radial probability

decreased ℓ = decreased E

What is the nuclear charge and shielding for 2s?

increased nuclear charge (over 2p) decreased shielding (by 1s)

What causes there be general trends for sub levels?

shielding and penetration

What happens to the shielding and penetration…when ℓ is smaller?

What is the sub shell order for energy?

greater penetrations

lower shielding

s < p < d < f

What are two examples of quantum mechanics providing theoretical explanations for experimentally based periodic table?

- electron assignments

- electron distributions in shells and sub shells - ground state electron configurations

- lowest energy distribution of electrons

What is the Aufbau Principle?

Starting at the beginning of the periodic table…

add 1 electron to the next lowest energy sub shell for each atom.

What are the two ways to represent the subshells using the Aufbau Principle ?

- electron configuration

- shorthand designations for energy level

- nℓ^# - orbital diagram

- represents orbital and spin

- up and down arrow for spin

What is the order you fill the sub shells?

1s 2s 2p 3s 3p 4s 3d 4p 5s 4d 5p 6s 4f 5d 6p 7s 5f 6d 7p