1. Next Class is Review Day, Unit Test on Tuesday!
Please take out:
Your lab notebook
Ionization Across the Nation
HW Sheet
Ask your partner:
“How are you planning on studying for our test on Tuesday/Wednesday?”
SCIENCE, MY FAVORITE!

2. Warm-up
As you move across a row in the Periodic Table for any period, the sizes of the atoms _____________. Knowing that, provide an explanation for the ionization energy trend within a period.
Claim: As you move left to right on the PT, the ionization energy ________________.
Evidence: (Give examples from page three on your homework packets)
Reasoning: WHY?!?! Connect to electronegativity and atomic radii 
decrease
Increases/decreases
Evidence: Lithium IE=520, Neon IE=2080 OR Na IE=496 and Ar IE=1520
Reasoning: If Atoms atomic radii gets smaller as you move across the PT in any period, this is because the number of protons increase. The more protons (+) the more pull you have on electrons (-). As atomic radii decrease because the atoms hold the electrons closer, our electronegativity, the ability for atoms to attract electrons increases. Thus our IE more increase, if atoms are holding electrons tighter it will cause the amount of energy needed to remove it to increase.

3. HW Review Check your answers with the answer key with your lab group
Log this on your HW sheet
Turn in your HW sheet
Start thinking about Nuclear Reactions (the last part of our unit!)

4. Learning Targets

5. Nuclear Chemistry
AKA– Why shouldn’t I stand in front of a microwave for extended periods of time?

6. Uranium-238 is used in nuclear reactors to generate electricity
Uranium-238 is used in nuclear reactors to generate electricity. In the nuclear reactor, uranium-238 changes to lead-209.
How can atoms of uranium-238 change into atoms of lead-209?
𝑈  𝑃𝑏
The nuclear reaction is initiated by colliding the uranium-238 with 0 1 𝑛 . What do you think this symbol ( 0 1 𝑛 ) represents?
Think-Pair-Sharee

7. Group Presentations 10 min… GO!
What group am I?
Fusion- Xe, I
Alpha Decay- Au, Bi
Beta Decay-O, Hg
Gamma Rays- Cu, Al
Group Presentations 10 min… GO!
Your Group Must:
1. Create a physical model that demonstrates the nuclear process.
2. Present a working model to the class of how the process works.
Your Whiteboard must answer the following:
1. An Analogy of what the process is like.
2. What do humans use this for?
3. How does this process impact life?
4. Provide an equation using elements commonly in this process.
5. (Fission and Fusion) What forms of radiation are released by this process? (Decays) What stops this type of decay?
Use internet & textbooks. 20 mins?

8. What does this have to do with anything?

9. Nuclear Notes

10. What do you think the black regions are?
N= neutrons Z= protons
What do you notice?
What do you think the black regions are?
What do you think the blue regions are?
Notice how elements below 20 the proton to neutron ratio is =1, and after 20 the neutrons are >1. What role do you think the neutrons play?
All elements above 83 are radioactive, what do you think that means?
No longer 1:1 ratio

11. Types of Nuclear Reactions- First Type
Fusion- one element breaks into two
Uranium-235  Barium Krypton n0
This releases a HUGE amount of energy. This was the fission bomb used in WWII!
Remember to conserve mass!

12. Types of Nuclear Reactions- Second Type
Fusion- Combines two light nuclei into one heavier element
Produces even more energy than fission
This is what happens in stars
Alpha decay- loss of an alpha particle (a Helium nucleus, 2 4 𝐻𝑒 )
𝑈 → 𝑇ℎ 𝐻𝑒
Beta decay- loss of a beta particle (a high energy electron, −1 0 𝑒 )
𝐼 → 𝑋𝑒 + −1 0 𝑒

13. Want to twist your brain a little bit?
Recall:
Nucleus has all the mass. The mass of an atom is equal to all the protons plus all the neutrons.
Example:
He atom:
2 protons + 2 neutrons
2( amu) + 2( amu) =
BUT THE ATOMIC WEIGHT OF Helium-4= !
Why does the mass differ if the atomic mass = # of p+ + # of n0?

14. The mass difference is due to the release of energy!
EINSTIEN!
Remember E=mc2??
The mass difference is due to the release of energy!
Energy is released upon the formation of a nucleus, the nucleus is lower in energy than its parts!

15. So…
If energy is released to break up the nucleus into its parts, the higher the binding energy the more stable the nuclei (since the nucleus would be more favorable in terms of energy).

16. Nuclear binding energy… why do stars stop at Iron?
It is no longer favorable to form atoms!

17. Rest of class
Work on Formation of Elements Worksheet (finishing this is homework)
Class discussion—If Time allows
Free write is our exit task NOT IN OUR NOTEBOOKS

18. Class discussion What does it mean to be radioactive?
Why are radioactive elements unstable?
If an element spontaneously undergoes radioactive decay, would you expect to find it in nature? Why or why not?

19. Free Write on Nuclear Reactions:
Compare and contrast physical/ chemical/ nuclear reactions.
QUESTIONS? Write them at the bottom of the page and circle it