Transcript Do Now – 11/10/09 - Schurz High School

Design a firework and draw/color it in
the space for your “Do Now” for
today.
• Why did you pick the shape that
you did?
• Why did you choose the colors that
you did?
• No lab today =( Gas lines not
working – we will do it on Thursday.
Sorry guys.
Do Now – 11/10/09
HW for this week
• Due: Nov 12 (Thu)
• Create a poster of the entire Electromagnetic
Spectrum: (10 pts)
* Visible light must be in color (Think Roy G. Biv
(Red, Orange, Yellow, Green Blue, Inidgo, Violet)
* Label all EM Radiation clearly
* Name, prd, date
* Extra 2 points for artictic creativity
* Look online and in your book for the necessary
information.
New-ish Cornell Note format
•Copy the light blue headings of the slide to the
left side.
•Copy the red writing onto the right side.
•ONLY copy information that is missing from your
notes from last week.
Electromagnetic Radiation
• Defined as energy that exhibits wavelike behavior.
• Waves are characterized by:
– Wavelength (λ): The distance between successive crest or
troughs. Measured in m, cm, nm.
– Frequency (υ): The number of waves that pass a given
point per second. Measured in 1/s (s-1) or Hertz (Hz).
– Amplitude: The waves height from the origin to the crest
or the trough.
– C = speed of light, is a constant (always known, never
changes) = 3.00 x 108 m/s
c=λxυ
So what does c = λ x υ really show?
• If you take any wave and multiply the
wavelength λ by the frequency υ, you will get
the speed of light c.
• Use this equation to solve for questions asking
you about wavelength or frequency.
• What can you infer about the relationship of a
wave’s wavelength and frequency?
– Inversely related: if one gets bigger, the other gets
smaller
Electromagnetic Spectrum (EM Spectrum)
• Encompasses all forms of electromagnetic radiation.
– Visible light is the most familiar example of
electromagnetic radiation. Differences in the
wavelength of visible light are manifested as
different colors.
Visible Light
• The small range of light in the EM spectrum that humans can see
with the naked eye (about 400 to 800 nm)
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• ROY G. BIV: Red, Orange, Yellow, Green, Blue, Indigo, Violet (in
order of longest to shortest wavelength)
Bohr Model (yes, copy this all down)
• Based on the hydrogen atom
• Key points:
– Electrons are in specific orbitals around
the nucleus
– Ground state: orbital closest to nucleus,
lowest in energy
– Excited states: Orbitals further away are
higher in energy
– Absorb light – electron goes from
ground state to excited state
– Emit light – electron goes from excited
state to ground state
Atomic Emission Spectra
• Electrons can move between orbitals of FIXED
energies
• Only SPECIFIC wavelengths of light can be
absorbed and emitted
• Atomic Emission Spectrum: the unique
pattern of light emitted by a specific atom
Atomic Emission Spectrum
• When an element is heated in a flame, the emission
spectrum will appear to be just one color to the naked eye.
Identifying Elements using Atomic
Emission Spectra!
Match each of the following atomic emission
spectra to the ones you drew to identify the
element! Write the name of the element on
your sheet!
Helium
Krypton
Hydrogen
Xenon
Up In Flames! Model Lesson
Materials
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Chemical compounds
2- 100 mL beakers
1- 250 mL beaker
Cotton swabs
Energy source
– Bunsen burner
• Matches or strikers
Summary
• Visible light differs in color based on different
wavelengths
• Atoms can absorb specific quantities of energy
based on how electron arrangement
• Each atom has an unique atomic emission
spectrum (so we can identify it!)
Up In Flames! Model Lesson
Yellow
Orange
Sodium (Na) Calcium (Ca)
Red
Lithium (Li) Strontium (Sr)
Plain
Purple-Violet
Potassium (K)
Blue
Copper (Cu)
White – Silver
Magnesium (Mg)
Up In Flames! Model Lesson
Sodium
Yellow
Calcium
Orange
Potassium
Purple