Atomic Spectra and Flame Test

The Lab What observations did you make observing White Light?

The Lab What observations did you make looking at the spectrum tubes of Hydrogen, Helium, and Neon? What observations did you make looking at the Fluorescent Lights?

Hydrogen Hydrogen Helium Neon

Why??!! This property of different elements puzzled scientist for years Einstein, Bohr, Heisenberg, Plank, Schrodinger To understand what is going on… Light The Atom

Light and the Electromagnetic Spectrum

Light and the Electromagnetic Spectrum Light Behaves Like a WAVE!! Has a WAVELENGTH Relationship between Wavelength and Energy!! LONG Wavelength is LOW energy SHORT Wavelength is HIGH energy Long Wavelength Short Wavelength

Light and the Electromagnetic Spectrum Light Behaves like a PARTICLE!! Proposed by Einstein Said that Light was tiny “packets” of energy Those packets he called PHOTONS Einstein said that photons are QUANTIZED Each photon has a Specific amount of energy Used this to explain the Line Spectra of atoms

The Atom What is the structure of an Atom? Made of Protons, Neutrons, and Electrons Nucleus – Protons and Neutrons Electron Orbitals or Clouds – Electrons

The Atom A few problems with the atom: Bohr’s Model All those protons in the nucleus The electrons and the protons All those electrons round the nucleus Bohr’s Model Nucleus has protons and neutrons Electrons in ORBITS Imagine a “solar system “

The Atom Einstein and Bohr’s Model Photon strikes and atom in its GROUND STATE Photon is a quantized amount of energy - Atom absorbs that energy Atom enters and EXCITED STATE Then the atom emits that extra energy Atom returns to the GROUND STATE But HOW does that explain the Line Spectra!!??

The Atom First thing is to figure out what ACTUALLY absorbed that extra energy form that photon… What are our choices? Proton Neutron Electron What is the most likely choice!?

The atom THE ELECTRONS!!! I need a Volunteer! Let’s take a look at a LIVE DEMO!! I need a Volunteer!

The Atom Modern Model of the Atom: Electrons are in ORBITALS, Electron Clouds Not in ORBITS like planets Each ORBITAL has an associated energy Electrons can be EXCITED from a LOW ENERGY ORBITAL to a HIGHER ENERGY ORBITAL by absorbing a Photon When moving from a HIGH ENERGY ORBITAL to a LOWER ENERGY ORBITAL, the electron emits a PHOTON from the electromagnetic spectrum

The Atom

Flame Test and Spectrum Tubes Hydrogen’s Tube was Pink/Purpleish Hydrogen has blue and red spectral line Color blend

Flame Test and Spectrum Tubes Each element has a different set of spectral lines They blend to produce the colors we see in a flame test!

Why are spectral Lines useful? Pluto Nitrogen

Questions!?