1. Nuclear Chemistry

2. The Nucleus Inside the nucleus there are:
Protons
Neutrons
The nucleus is held together by the strong nucleus force.

3. The Nucleus The nucleus is not always stable!
The number of protons and neutrons can influence the stability of the nucleus.
Usually a 1:1 ratio is stable.
More than this is unstable
Certain isotopes of elements are said to be unstable, and as a result they break down  radioactive.
All elements with an atomic number above 82 have at least one radioactive isotope.

4. Radioactivity There are three major types of radioactivity:
Composed of 2 protons and 2 neutrons
A helium nucleus
Made of a single negative charge
Basically an electron
High energy photon
No mass

5. Types of Radioactivity
Alpha particles lost:
A nucleus loses 2 protons and 2 electrons
This produces a loose alpha particle and an atom that is “lighter” with an atomic number lower by two and an atomic mass lower by 4 amus.

6. Types of Radioactivity
Beta particles lost:
A neutron is made up smaller particles
In radioactive isotopes sometimes a neutron will spontaneously break apart, releasing a beta particle (electron).
What remains is a proton
The neutron breaks apart into a proton and an electron.
The electron is released from the nucleus and the proton stays.

7. Types of Radioactivity
Gamma Rays:
The most penetrating and high energy type of radioactivity.
Large amounts of photon energy is released
The nucleus is unchanged in numbers of protons and neutrons, but becomes more stable.

8. Strength of Radioactivity
Alpha particles are the most heavy but least penetrating.
Gamma rays are pure energy, have no mass, but are the most penetrating.

9. Nuclear Reactions
1. Fission: This occurs when a radioactive nucleus splits to form two smaller, more stable nuclei
This can lead to dangerous chain reactions!

10. 1. Fission: Nuclear Reactors and Bombs

11. 1. Fission: Nuclear Reactors and Bombs
A common source of Uranium-235 is used as a fuel in nuclear reactions.
It undergoes a number of reactions to release a great deal of energy, which in a reactor is harvested and used for power.

12. 1. Fission: Nuclear Reactors and Bombs
Another common source of fuel is Uranium-238
The end result of all of the reactions is a stable isotope of lead!

13. Nuclear Reactions
2. Fusion: This type of reaction involves two small nuclei coming together to form a larger nuclei.
This is how the sun works

14. 2. Fusion
Nuclear fusion produces an enormous amount of energy, more than fission.
However the reaction is very unstable and dangerous.
Can only be contained in stars like the sun.