OPENING QUESTION:

What *precisely* do we know about the armaments of the unruly inhabits of Mars? (And why do we care?)

How is a photon of light is created--- Please relate to your team with a well labeled sketch!

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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:

Here's some notes from yesterday:

Oh and by the by, I'm grading your graphing videos and I'm absolutely, totally digging it. By and large you *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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We didn't really get to this yesterday so I"ll offer it up again today:

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:

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. We don't really have to go into this much depth for our discussions but it's important for you to realize that electrons don't 'orbit' around the nucleus like miniature planets orbiting the sun.

The path's that electrons follow are dictated by quantum wave equations that take into account the physical properties of the atom. Additionally, the 'orbitals' shown are determined by probability. We KNOW that there is a very, very strong likelihood that certain electrons will be found in certain proscribed space around the nucleus.

We can never know the precise location of an electron, however.

That goes to Quantum Physics (specifically the Heisenberg Uncertainty Principle) which, simply stated, tells us that the more we know about the momentum of an electron, the less we know about its position and vice versa).

An additional tidbit: the more we try to ‘pin down’ the location of an electron, the more our act of measuring disturbs its actual properties—both position and momentum. It’s VERY mind-confuzzaling

 

<To reiterate from yesterday>:

Another 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:

 

We'll *glance* at this... just, well, because it's a nice transition from water waves to light waves

Let's take another gander at chart similar to what we saw yesterday:

Work with your team to identify the series AND steps required to generate the hydrogen emission spectra we saw yesterday:

You'll need to work with your team to do a wee bit o' research on the relationship between ROYGBIV and wavelength, frequency and energy:

Let's take a look at THIS basic photon sketching activity (Please note the actions/motions of the electrons and such in this activity are an excessively BASIC model to give us a better idea of what happens. They are not the *actual* paths taken by particular electrons.