Chem: Quantum Theory

Dual Nature of Light

light sometimes has properties of a wave and sometimes has properties of a particle. light is both a wave and a particle, but not at the same time. photon: light particle.

Quantum Theory of Light

• light has energy in a set amount called quantum

• ok because energy isnt matter

Neils Bohr

electrons can only have certain energies/locations around nucleus. electrons cannot spiral into nucleus because being between levels is not allowed. electrons can move from one location to another by gaining or losing quanta of energy.

Ground State

electrons have lowest energy and are as close to the nucleus as possible, electrons are stable

Excited State

electrons gain energy and move further from the nucleus, makes electrons less stable

Continuous Spectra

all colors of visible light (roygviv)

Absorbtion Spectrum

when white light passes through an element, certain colors/frequencies/energies of light will be absorbed by the electrons

• only those colors/frequencies/energies in allowable locations will be absorbed

• electrons go to excited state

Emission Spectrum

when elements have electrons in excited state, they can emit the same colors/frequencies/energies of light that were absorbed

• these colors/frequencies/energies correspond to allowable locations around the nucleus

• electrons return to ground state

Heisenberg: The Uncertainty Principal

• it is impossible to accurately measure the location and velocity of a particle

• the more accurately one of these is measured, the less we know about the other

de Broglie: Matter Waves

• applied dual nature of light concept to all particles

• electrons (and all moving particles) have a fundamental wavelength that they will show under certain conditions

  • only measureable on the atomic scale

Schrodinger: Wave Equation

solution to equation gives probability of finding electron in a given location/3-dimmensional volume by treating the motion of an electron like a wave