Waves. Chapter 8
Examination #1 Range was 0-109 pts Maximum pts =119 with the extra credit problem Average grade of Examination #1 =89.7 or 90 pts out of 109 Average of 82.6% Number of students that scored above 100 pts on exam 21 Highest grades..>108 Julia Zanotelli Kevin Salat Jennifer Poth Christian Metzier Bridget Mooney Nicolas Montoya Jameson Crawford Genevieve Bellon
Meteors typically cause sonic booms when they enter the Earth s atmosphere, and the one that occurred over Chelyabinsk was forceful enough to sha=er dishes and televisions in people s homes. Car alarms were triggered for miles around, and the roof of a zinc factory par@ally collapsed. Video clips, uploaded by the hundreds star@ng early Friday morning, showed ordinary mornings interrupted by a blinding flash and the sound of sha=ering glass. As residents of Chelyabinsk began their day on Friday, a 10- ton meteor around 10 feet in diameter was hurtling toward the Earth at a speed of about 10 to 12 miles per second, experts from the Russian Academy of Sciences reported in a statement released Friday. Scien@sts believe the meteor exploded upon hilng the lower atmosphere and disintegrated at an al@tude of about 20 to 30 miles above the Earth s surface not an especially unusual event, the statement said. NY Times Friday February 15, 2013
Asteroid: A rela@vely small, inac@ve body, composed of rock, carbon or metal, which is orbi@ng the Sun. Comet: A rela@vely small, some@mes ac@ve object, which is composed of dirt and ices. Comets are characterized by dust and gas tails when in proximity to the Sun. Far from the Sun it is difficult to dis@nguish an asteroid from a comet. Meteoroid: A small par@cle from an asteroid or comet orbi@ng the Sun. Meteor: A meteoroid that is observed as it burns up in the Earth's atmosphere - a shoo@ng star. Washington Post Meteorite: A meteoroid that survives its passage through the Earth's atmosphere and impacts the Earth's surface. h=p://www.universetoday.com/99950/watch- live- as- asteroid- 2012- da14- whizzes- past- earth/
Energy Transfer by Waves Wave A traveling disturbance Properties of waves Wavelength Frequency Velocity Amplitude
The Doppler Effect h=p://www.youtube.com/watch?v=zrgg7e9b5wy&nr=1&feature=fvwp h=p://www.youtube.com/watch?v=- d9a2oq1n38 Sonic Boom An echocardiogram uses sound waves to produce images of your heart. This commonly used test allows your doctor to see how your heart is bea@ng and pumping blood. Your doctor can use the images from an echocardiogram to iden@fy various abnormali@es in the heart muscle and valves. h=p://youtu.be/4cck1mxjhm0 Evidence that everything is moving away from us
The Electromagnetic Spectrum h=p://www.youtube.com/watch?v=58fs5yi8k9i
The Electromagnetic Spectrum
Heat Escaping from People
Visible Light Visible light Range: 700nm 400nm Colors Slices of electromagnetic spectrum
A Glass Prism Separa@ng White Light
Path of Light through the Human Eye
The Atom Chapter 8 Great Idea: All of the matter around us is made of atoms, the chemical building blocks of our world
Chapter Outline The Smallest Pieces The Structure of the Atom When Matter Meets Light The Periodic Table of the Elements
Dividing a Bar of Gold
Elements John Dalton Father of modern atomic theory Cannot break down elements Elements composed of atoms Example: Water molecule is 1 oxygen atom and 2 hydrogen atoms
Everyday Elements Helium, carbon, aluminum, copper, gold
The Structure of the Atom
The Nuclear Regulatory Commission Logo: highly stylized atomic model
Bohr Atom
Electron Energy Levels
Atomic Model
Photons: Particles of Light Photon absorbed Used to move electron to a higher energy state Photon emitted as electron moves to lower energy state
Photons: Par@cles of Light
Quantum leap or jump - electron disappears from original location and reappears in final locationnever at positions in between Photons - cont.
Spectroscopy Atoms emit and absorb different photons Depends on differences between energy levels Each atom has distinct set of photons Spectrum: all photons emitted by an atom Used for identification
Na, K, and Li Give Distinctive Colors to a Flame
Glass prism Spectroscopy cont.
Spectroscopy cont. Line spectra for H, Na, and Ne h=p://www.youtube.com/watch?v=l4yg4htm3uk
The Periodic Table of the Elements
The Science of Life Spectra of life s chemical reactions Used to determine how enzymes work Used to identify pollutants emitted from automobile exhaust pipes
Technology Lasers Produce a beam of light
The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation. The emitted laser light is notable for its high degree of spatial and temporal coherence.
Ac@on of a Laser
Lasers Have Many Uses
Periodic Table of the Elements Systematizes elements Columns contain similar elements Alkali metals: soft, silvery metals Noble gases: colorless, odorless, and inert
Periodic Table of the Elements
Why the Periodic Table Works: Electron Shells Patterns mirror arrangement of electrons in shells Pauli exclusion principle First shell 2 electrons, second shell 8, etc.