1. “Nuclear Reaction” – Anytime the nucleus of an atom changes.
Nuclear Chemistry
Nuclear Chemistry
“Nuclear Reaction” – Anytime the nucleus of an atom changes.

2. Types of Nuclear Reactions:
Radioactive Decay
Fission
Fusion

3. Radioactive Decay
Nucleus

4. Fission
The splitting apart of a large atom (nucleus) into two smaller atoms

5. Fusion
The combining of two small atoms to produce a single larger atom

6. So What’s the Point? The point is – You get a poop load of energy!
The products of a fission and a fusion reaction weigh less than the reactants.
In other words, matter disappears!
Where does the matter go?
It turns into energy!
According to the equation: E = mc2
The point is – You get a poop load of energy!

7. Fission
The splitting apart of a large atom (nucleus) into two smaller atoms

8. “Chain Reaction”

9. “Critical Mass”
When a hunk of fissionable material can keep reacting on its own

10. “Critical Mass”
When a hunk of fissionable material can keep reacting on its own
Most neutrons end up leaving the solid before they can hit another nucleus.

11. Thick Hunk = Chain Reaction!
“Critical Mass”
When a hunk of fissionable material can keep reacting on its own
Thick Hunk = Chain Reaction!

12. The Louis Slotin Accident
On May 21, 1946, Louis Slotin and seven other colleagues performed an experiment that involved the creation of one of the first steps of a fission reaction by placing two half-spheres of beryllium (a neutron reflector) around a plutonium core. The experiment used the same 6.2-kilogram (13.7 lb) plutonium core that had earlier irradiated Daghlian, later called the "Demon core" for its role in the two accidents. Slotin grasped the upper beryllium hemisphere with his left hand through a thumb hole at the top while he maintained the separation of the half-spheres using the blade of a screwdriver with his right hand, having removed the shims normally used. Using a screwdriver was not normal part of the experimental protocol.
At 3:20 p.m., the screwdriver slipped and the upper beryllium hemisphere fell, causing a "prompt critical" reaction and a burst of hard radiation. At the time, the scientists in the room observed the "blue glow" of air ionization and felt a "heat wave". In addition, Slotin experienced a sour taste in his mouth and an intense burning sensation in his left hand. Slotin instinctively jerked his left hand upward, lifting the upper beryllium hemisphere and dropping it to the floor, ending the reaction. However, he had already been exposed to a lethal dose of neutron and gamma radiation.
"As soon as Slotin left the building, he vomited, a common reaction from exposure to extremely intense ionizing radiation" recorded Dr Thomas D. Brock. Slotin's colleagues rushed him to the hospital, but irreversible damage had already been done. His parents were informed of their son's inevitable death and a number of volunteers donated blood for transfusions, but the efforts proved futile. Louis Slotin died nine days later on May 30, in the presence of his parents. He was buried in Winnipeg on June 2, 1946.
The Louis Slotin Accident

13. “Critical Mass” (Abombs)
When a hunk of fissionable material can keep reacting on its own

14. The Nagasaki Bomb - Compared to the one used on Hiroshima, the Nagasaki bomb was rounder and fatter. It was called "Fat Man." The material used was plutonium The fission of slightly more than one kilogram of plutonium 239 is thought to have released destructive energy equivalent to about 21,000 tons of TNT.
The Hiroshima Bomb - Due to its long, thin shape, the Hiroshima bomb was called ³Little Boy². The material used was uranium 235. It is believed that the fission of slightly less than one kilogram of uranium 235 released energy equivalent to approximately 15,000 tons of TNT

16. Hydrogen Bomb
50 Million tons TNT
Fission of Pu
Fusion of H

17. Why are some atoms radioactive?

19. Why are some atoms radioactive?
1) They don’t have the “proper” ratio of protons to neutrons.

20. Why does it end here?
(atomic number 83)

21. “Electrostatic Force”
A Nucleus
“Electrostatic Force”
What do “like” charges do?
Why don’t the protons
fly apart?
There has to be a stronger force inside the nucleus holding them together!
yellow = protons (+)
orange = neutrons
Strong Nuclear Force

22. Strong Nuclear Force Weak Nuclear Force Electrostatic Force Gravity
The strong nuclear force is the strongest of all the forces of nature.
But…
It only works over VERY small distances!

23. Strong Nuclear Force A BIG Nucleus pink = protons (+) grey = neutrons
Becomes ineffective at a distance that is equal the diameter of a Bismuth nucleus.
too far apart
pink = protons (+)
grey = neutrons

24. So the electrostatic force takes over.
A BIG Nucleus
Strong Nuclear Force
Becomes ineffective at a distance that is equal the diameter of a Bismuth nucleus.
too far apart
So the electrostatic force takes over.
high speed ejection
pink = protons (+)
grey = neutrons
“Alpha Decay”

25. Why are some atoms radioactive?
1) They don’t have the “proper” ratio of protons to neutrons.
2) They are too big.

26. Alpha Decay – emits a helium nucleus
loses 2 protons and 2 neutrons
Beta Decay – emits an electron
neutron turns into a proton
Electron Capture – absorbs an electron
proton turns into a neutron

27. Radioactive Decay

28. Nuclear Radiation

29. “Radiation” Nuclear vs Electromagnetic