The Quantum Model of the Atom

Proposed that the photoelectric effect could be explained by the concept of quanta, or packets of energy that only occur in specific amounts. Einstein expanded this concept to propose that all electromagnetic radiation has this dual wave- particle nature. He proposed the photon, a mass- less particle that carries a quantum of energy. Max Planck

Emission Spectra Elements will emit light of certain frequencies as their electrons return from the excited state to the ground state. Each has a unique pattern that makes it identifiable (like a fingerprint).

His model of the Hydrogen atom sought to explain how the gas could emit only certain frequencies, and thus colors, of light. It was successful in explaining H, but failed to do so with multi-electron atoms. Niels Bohr

In 1924 he proposed that electrons, like light, may demonstrate wave-particle duality. Experiments like the double-slit experiment opened the door to verification of quantum ideas.double-slit experiment Louis de Broglie

Developed the wave equations that describe mathematically the wave properties of electrons and other small particles. These equations define the probable locations of electrons, or orbitals. Erwin Schr Ö dinger

Developed the Uncertainty Principle which states that is impossible to determine simultaneously both the position and velocity of a particle. The act of observing changes the event! Let’s let some prominent physicists explain. explain Werner Heisenberg Say my name?

Heisenberg Humor I’m not the Heisenberg we’re talking about…II

Atomic Orbitals Atomic orbitals and the electrons in them can be described by a set of four quantum numbers.

1.Principal Quantum Number (n) tells how many energy levels (or shells) are occupied by electrons. Values from 1-7. Increase values indicate higher energy and further distance from the nucleus. 2.Angular Momentum Quantum Number (l) indicates the shape of the orbital. There are 4 main shapes designated s, p, d and f. 3.Magnetic Quantum Number (m) indicates the orientation of the orbital around the nucleus along the x, y and z axis’. 4.Spin Quantum Number indicates the possible spin state of the electron. Values are +1/2 and -1/2. Quantum Numbers

Basic orbital shapes

S = Spherical P = Peanut D = Double peanut F = Flower Mnemonic for Orbital Shapes