1. Nuclear Radiation

2. Nuclear Chemistry? Or Quantum Physics?
What we have learned in this course is the nucleus consists of protons and neutrons. This is an oversimplification as there is a lot more going inside the nucleus!
For one, how in the world do positively charged particles – which REPEL – exist together in a tightly packed nucleus?!?
A very strong force holds the nucleus together, fittingly called the “strong force”
The presence of neutrons stabilizes the nucleus; more protons requires more neutrons to make it stable
What else is in the nucleus? Turns out – plenty!
Quarks, they come in 3 different colors of 6 different flavors: up, down, top, bottom, strange, and charm
Leptons, they also come in 6 flavors: electron, muon, tau, and their associated neutrinos
Or Quantum Physics?
chemistry is more concerned with chemical reactions on the atomic level, you can learn more about these particles in advanced physics

3. Radioactivity
In 1903, Marie Curie along with Pierre (her husband) and Antoine Bequerel, win the Nobel prize in physics for their work on radioactivity.
They showed that energy emitted from uranium salts fogged photographic plates
They called this energy radiation and the process radioactivity
Marie Curie died in 1934 from leukemia, caused by her long term exposure to radiation.

4. Radioisotopes
Chemical reactions involve changes in the number and arrangement of electrons to gain stability
Nuclear reactions involve changes in unstable nuclei (radioisotopes) that always emit large amounts of energy
Unlike chemical reactions, nuclear reactions are not affected by changes in temperature, pressure, or catalysts
Radioisotopes will decay regardless of the compound in which they are found

5. Why are some isotopes radioactive?
Just as electrons are more stable in certain numbers and arrangements
Nuclei are more stable in certain sizes and compositions
The ratio of neutrons to protons is very important to nuclear stability
Very large nuclei are also unstable
These nuclei spontaneously decay and emit radiation to achieve nuclear stability

6. Radioactivity Radiation is emitted during radioactive decay
There are three main types of radiation:
Alpha radiation
Beta Radiation
Gamma radiation
Some other types:
Positron
Neutron
neutrino

7. Alpha Particles 4 2 +2 He
Alpha particles are helium nuclei emitted from a radioactive source
Each consist of two Protons and two neutrons and have a +2 charge

8. Beta Particles e -1
If neutron:proton is too high, a neutron will decay, emitting a beta particle
What is left is all the mass of the neutron, and a positive charge
So a neutron  proton and a beta particle is ejected
Same properties as an electron
No mass, -1 charge

9. γ Gamma Ray
Gamma Rays are high energy photons emitted by radioactive isotopes
Similar to x-rays
No mass
No charge
Most powerful form of radiation
Gamma Rays are usually emitted along with alpha or beta particles during radioactive decay

10. More Radioactivity