Quantum Theory

Quantum theory

describes mathematically the wave properties of electrons and other very small particles

Heisenberg

electrons detected by their interaction with photons, Heisenberg uncertainty principle states that it is impossible to determine simultaneously both the position and velocity of an electron or any other particle

Quantum numbers

specify the properties of atomic orbitals and the properties of electrons in orbitals

Defraction

the bending of waves around a barrier or through an opening

Orbital

three dimensional region around the nucleus that indicates the probable location of an electron, can hold up to two electrons, orbital shapes are defined as the surface that contains 90% of the total electron probability

Schrodinger

used dual wave-particle of nature to develop equation that treated electrons as waves, along with the uncertainty principle his wave equation laid foundation for modern quantum theory, a set of four quantum numbers are plugged into Schrodinger's equation, we get a probability distribution of where the electron is

Magnetic Quantum Number (m)

describes orientation of the orbital about the nucleus, there is 1 version of an s orbital in the s sublevel, there are 3 versions of a p orbital in the p sublevel, there are 5 versions of a d orbital in the d sublevel, there are 7 versions of an f orbital in the f sublevel, ALL orbitals within a sublevel have the same energy - referred to as degenerate orbitals, ALL main energy levels have their own set of sublevels

Angular Momentum Quantum Number (sub level quantum number l)

describes the shape and sub levels of a orbital, each sub level has a shape (s,p,d,f), designated by principal quantum number followed by letter of sublevel

Principle Quantum Number (n)

describes the size of the orbital, or distance of the orbital from the nucleus indicates size of electron field, must be a positive integer, number of electrons that can fit in a shell is 2n^2

Spin Quantum Number (m )

describes the state of the electron, each orbital can hold two electrons so long as they have opposite spin, two possible values m = + 1/2 or - 1/2, spinning electron produces a magnetic field, oppositely spinning electrons produce opposite fields

How is Bohr's model wrong?

did not explain why electrons were confined to specific energy levels, why they could not exist between energy levels, only worked for hydrogen elements, did not explain lines found outside the visible spectrum

How can a wave be a particle and a particle also be a wave?

Einstein- light as a collection of one or more photons propagating through space as electromagnetic waves

Refraction

The bending of a wave as it passes at an angle from one medium to another

Aufbau Principle

an electron occupies the lowest-energy orbital that can receive it

Broglie

believed that electrons could have wavelike properties, waves could only exist at certain frequencies, did experiments found that electrons defracted, refracted, and infered, dual wave-particle of nature

Pauli Exclusion Principle

no more than two electrons can occupy a space orbital, and these two electrons must have opposite spins

Hund's Rule

orbitals of equal energy are each occupied by one electron before any orbital is occupied by a second electron, and all electrons in singly occupied orbitals must have the same spin

Photon

particle of electromagnetic radiation with no mass that carries a quantum of energy

Photoelectric Effect

phenomenon observed when light of a certain frequency is incident on a sheet of metal and causes it to emit an electron

Wave-Particle Duality of Nature

principle that states that both wave and particle concepts must be retained, because wave-like properties are exhibited in some experiments and particle-like properties are exhibited in others