Super Model How are protons and electrons arranged in atoms?

Notebook Super Model, Part 1 Put it in your TOC How are electrons and protons arranged in an atom? Put it in your TOC

Page 162 Different spectra caused by differences between atoms Questions we’re asking: HOW are they different? How does the structure of an atom vary from element to element?

Models What does a model do? What does it allow us to do that we normally wouldn’t do? http://www.youtube.com/watch?v=xqNSQ3OQMGI

Page 167 – What is a Model? Physical Model Conceptual model An object on a different scale Example? Conceptual model Describes a system, not a thing

Example of model - DNA

Example of model - Gravity

Blind Drawing Activity One person come up to the board Feel an object in their hands, EYES CLOSED Have 20 seconds to draw it on the board You are modeling using evidence…

Black Box Activity Eight groups Each group chooses a SECRET object Place the object in the box at your station Make sure others don’t see it Go around and record what you observe/test for the other boxes Make a guess You can walk around alone or in a group

Process and Procedure #1: Read 164-165 INSTEAD of #2: Explain Rutherford’s experiment by using a sentence for each of these words. Show how it is related to the reading/experiment. Use these words: Gold foil, alpha particles, nucleus, empty space, rebound, target, model, protons, electrons, positive, negative DUE MONDAY

Web stuff http://www.mhhe.com/physsci/chemistry/essentialchemistry/flash/ruther14.swf

Stop and Think, p. 169 Let’s just discuss #2 Good discussion looks like what? Respectful Quiet when it’s not your turn Creative

History of the Atom The modern model of the atom has evolved over a long period of time through the work of many scientists Democritus matter is made up of particles called atoms Dalton atoms of the same element are alike solid indivisible spheres Thomson cathode ray tube discovers electrons plum pudding model

History of the Atom Rutherford Gold foil experiment discovers a massive (heavy) positively (+) charged nucleus most of the atoms volume is empty space nuclear model

History of the Atom Continued Bohr Schrödinger Hydrogen emission spectra electron energy is quantized – electrons can only have certain orbits with certain radii planetary model Schrödinger Aided by many famous scientists (De Broglie, Heisenberg, etc…) Wave-mechanical or electron cloud or quantum-mechanical model (very complex)

History of the Atom

Question: Subatomic particles can usually pass undeflected through an atom because the volume of an atom is composed of (1) an uncharged nucleus (2) largely empty space (3) neutrons (4) protons þ

Question: One model of the atom states that atoms are tiny particles composed of a uniform mixture of positive and negative charges. Scientists conducted an experiment where alpha particles were aimed at a thin layer of gold atoms. Most of the alpha particles passed directly through the gold atoms. A few alpha particles were deflected from their straight-line paths. An illustration of the experiment is shown below.