Nuclear Changes

1. Nuclear Changes

2. Matter can undergo several types of changes including: • Physical changes • Chemical changes • Nuclear changes Nuclear changes involve the most amount of energy.

3. Nuclear Transformations Nuclear transformations are reactions that occur in the nucleus of the atom. They result in a change in the number of protons and neutrons and will change the nature of the element (and therefore its characteristic properties).

4. Radioactivity Radioactivity can be described as a nuclear reaction that happens naturally. It is a property of unstable atoms. A radioactive substance will give off three types of rays: (1.) Alpha rays, α, are positively charged. They are also quite large, a piece of paper can stop them. (2.) Beta rays, β, are negatively charged. They are also much lighter than alpha rays and so can penetrate matter much better. A piece of metal foil, 3mm thick is needed to stop them. (3.) Gamma rays, γ, are neutral. This type of ray is not made up of particles, but rather pure energy. They are able to penetrate matter the most. In order to block their path, a very dense material like concrete or lead is used.

5. Types of Nuclear Transformations Nuclear reactions can also be provoked. These types of reactions require much energy to be begun. We begin this type of reaction by bombarding the nuclei with particles or other nuclei at very high speeds. This results in one of two types of nuclear reactions: nuclear fission and nuclear fusion.

6. Nuclear Fission Nuclear fission is a nuclear reaction in which the nucleus of a large atom is broken down into two or more nuclei in order to form lighter atoms.

7. Nuclear Fusion Nuclear fusion is a nuclear reaction in which two nuclei are joined in order to form a larger atom.