OPENING QUESTION:
How many different types of light waves can you list? <go!>
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LEARNING TARGET: I will be able to model how photons are created during today's class.
WORDS O' THE DAY:
- photon (a wave AND a particle of light)
- electromagnetic waves
- energy levels
- excited (electron) = ("electrons 'jolted' into a higher energy level")
- ground state (electron) = ("electrons existing on the lowest energy level")
CALENDAR:
WORK O' THE DAY:
Ya Know -- time to switch groups.
Please grab a calculator:
- Select the ex function
- Type in a '.' to start
- Add your birthday in MMDDYY format
- Hit {Enter}
- Write down the 5th, 4th & 3rd digit (in that order if you please!)
- Order yourself in the appropriate place in the appropriate way (GO!)
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Oh and by the by, I'm grading your graphing videos and I'm absolutely, totally digging it. You guys *crushed* this one.
I strongly, STRONGLY recommend that you copy that video to some permanent location outside of your school/PSD/Google Drive. You've learned a massive amount of advanced and in some instances very technical graphing concepts, tips and tools. You WILL forget HOW to do many of them but you will very likely recall that you did the work. Having that training video to refresh your recollections will be really helpful.
Again, VERY nicely done
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Now let's look at a sketch of a neutral hydrogen (that means protons are in balance with electrons) atom. Many of us imagine a VERY basic sketch that looks like this:
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which turns out to be a VERY simplified model of a hydrogen atom....have a conversation with your group about what that's so antiquated.
Now let's take a gander at a much more modern model of the electron orbitals for the innermost "orbital" layers surrounding an atom:
If you've taken chem you've learned chapter and verse about orbitals so I won't go much further on that.... if you haven't taken chem, make sure that you do!
One of the most intriguing and baffling concepts in ALL of science (IMHO of course) is that when an electron "jumps" to a higher energy level or when it "jumps" back down to a lower energy to produce light the time for each of those "jumps" is precisely..........
<wait for it..............................................>
<............................................................................................are you still waiting?>
ZERO Seconds!!! <let's discuss>
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Let's grab some goggles and take a gander at the spectrum of hydrogen light:
I'll also pass out some filters and you can see how different colored filters block different types of light.
Side Note:
The strong red line is called the "hydrogen alpha" line because it is the brightest hydrogen line.
The glass tube on the back counter contains hydrogen gas.
When I place that tube in a high voltage source the electrons instantaneously "jump" to a higher energy level where they remain "excited" (that is the correct physics term by the way).
To return to a lower energy level they emit a photo of a VERY specific type of light.
Most of the electrons take a path "back down" to a lower energy state that emits a specific color of red light. That makes for a brighter more vibrant color.
Fewer electrons take the path "back down" to a lower energy state that results in a particular color of violet light so that line is dimmer.
Here are the paths that electrons from hydrogen can 'jump up' to higher energy levels and 'jump back down' to lower energy levels:
Notice just how complex that system is. Keep in mind that is for the simplest of all atoms (hydrogen) with only 1 electron. Imagine how complex that is for atoms with more electrons!!!
Remember, light comes in MANY forms:
Rowdy Martians Invade Venus Using Xray Guns
The "Lyman Series" of electron quantum leaps produce light with too much energy for our eyes to see (ultra-violet)
The Balmer Series actually produces the visible light that we see as shown in the spectrum below:
If time permits: