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Democritus

First coined the term 'atoms'

Einstein

Explained the "photoelectric effect" by proposing that light is both a wave and a particle

Planck

proposed that atoms accept ONLY specific amounts of energy called quanta

Dalton

proposed that all matter is made up of atoms and established ideas about how atoms combine to form compounds in definite proportions.

Bohr

proposed that electrons orbit the nucleus in circular orbits (solar system model)

Thomson

positive and negative charges make up his plum pudding model.

Millikan

determined the mass to charge ratio of an electron

Rutherford

discovered the nucleus

Photoelectric Effect

uses stopping voltage to determine the energy of electrons, and enabled Planck's constant to directly relate frequency to energy.

increases

As energy increases, frequency______?

Red

Which has lower energy? Red of Violet?

Wavelength

Distance between corresponding points on adjacent waves. Length of one complete wave.

Frequency

number of waves that pass a point during a certain time period. Defined as the number of waves that pass a given point in a specific time (1 second)

Amplitude

distance from the origin to the trough or crest.

Quanta

energy that is emitted in small specific amounts.

Photoelectric Effect

the emission of electrons from a metal when light shines on a metal.

Frequency+wavelength formula

C=λv

Inversely

Frequency+wavelength are_____proportional.

Higher

Low energy waves have _____ frequencies.

Length of visible spectrum

400nm-700nm

Violet

Which has higher energy? Red or Violet?

Photon

bundles of light energy that is emitted by electrons as they go from higher energy levels to lower energy levels. Particle of electromagnetic radiation having zero mass and carrying a quantum of energy.

Each element has a unique bright-line emission spectrum

What is the significance of the Line Emission Spectrum?

Proportional

Energy of a photon is ______ to its frequency.

Energy+Frequency Formula

E=hv

Energy+wavelength Formula

E=hc/λ

Hertz (Hz)

what is frequency measured in?

Joules (J)

what is energy measured in?

meters, nm, etc

what is wavelength measured in?

Planck's constant

6.6262*10^34 J.s

C=speed of light

3.00*10^8

Orbital

region in space where there is 90% probability of finding an electron. "electron cloud"

Two

Each orbital can hold___electrons

Two

The S sublevel has____electrons

One

The S sublevel has___orbitals

Three

The P sublevel has______orbitals

Six

The P sublevel has_____electrons

Five

The D sublevel has____orbitals

Ten

The D sublevel has____electrons

Photon

When the electrons falls to a lower energy level, a _____ is emitted.

Size of the orbital

What does the energy level tell you?

Aufbau Principle

electrons fill the lowest energy orbitals first. An electron occupies the lowest-energy orbital that can receive it.

Pauli's Exclusion Principle

Each orbital can hold TWO electrons, but they must have opposite spins.

Hund's Rule

Within a sublevel,place one electron per orbital before pairing them up. "urinal analogy"

Ground State

lowest energy state of an atom

Excited State

a state in which an atom has a higher potential energy that it has in its ground state.

Principle quantum number

symbolized by n, indicates the main energy level occupied by the electron.

Angular momentum number

symbolized by l, indicates the shape of the orbital
s-spherical
p-dumbbell

Magnetic quantum number

symbolized by m, indicates the orientation of an orbital around the nucleus.

Spin quantum number

has only two possible values (+1/2, or -1/2) which indicate the two fundamental spin states of an electron in an orbital

Higher

As the wavelenght become shorter, the energy is______.

Bohr Model

electrons orbit the nucleus in circular paths of fixed energy.

Quantum Numbers

specify the "address" of each electron in an atom

S-orbitals

electrons are found within a sphere around the nucleus

D-orbitals

most appear to be the combination of two p-orbitals, "daisy"

P-orbital

orbital that look like "dumbbells or propellers" or tear drops.

F-orbitals

really complicating structure.

n

# of sublevels per level

n^2

# of orbitals per level

Dalton

All atoms of the same element are identical, other atoms are different. Proposed that atoms are small, uniformely dense, and indivisible.

Crooke & Thomson

used a cathode ray tube. Determined that atoms also contain witin themselves small negatively charged particles. They discovered the electron, the 'first' subatomic particle.

Rutherford

He tested Thomson's model with the gold foil experiment. According to Thomson's model, radiation particles should not be deflected. but in his experiment, some radiation was deflected.

Chadwick

Discovered the neutron. He reevaluates data and proposes that the radiation was actually a "massive" particle.

Planck

will only accept energy in small 'quantized' packets.

Broglie

Applied wave-particle theory to electrons. Found that electrons exhibit wave properties.

Schrodinger

The wavefunction helps describes the location of the electron, and its probable location. Electrons have a wavelenght.

Ion electron configuration

write the electron configuration for the closest Noble Gas

Ion formation

Atoms gain or lose electrons to become more stable.

Heisenberg Uncertainty Principle

impossible to know both the velocity and position of an electron at the same time.

Pauli Exclusion Principle

no to electrons in an atom can have the same 4 quantum numbers.

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