As you come in to the classroom, do the following: - Get a colored sheet of paper from the front lab table (we will use this later in class) - Copy the following on a sheet of notebook paper, and title your notes: radioactivity

Test Reflection

The Most Radioactive Places on Earth https://ed.ted.com/featured/HQg9hUhC/review_open#question-1

ABG’s of Radioactive Decay - Fold your paper like a pamphlet, so there are three sections.

ABG’s of Radioactive Decay Label the front of your tri fold

On the back of your tri-fold write: Radioactivity occurs when the nucleus of an unstable atom breaks down in a process called radioactive decay After decay, these atoms change into more stable atoms, sometimes of a different element.

We are still on the back! Here are examples of radioactive decay equations. The nucleus/nuclei on the left of the arrow is known as the parent nucleus (what you start with) The nucleus/nuclei on the right side of the arrow are the daughter nucleus/nuclei (what you end up with) daughter nuclei parent nuclei

Radioactive Decay Label the sections of your tri-fold with the 3 main types of radioactive decay: 1. Alpha 2. Beta 3. Gamma alpha beta gamma

Alpha Decay Symbols Model They are made of 2 protons and 2 neutrons. Alpha particles are the largest the three types of decay. Alpha particles are the slowest, least energetic, and least dangerous of the three. Alpha particles can be stopped by clothing, or a sheet of paper. Symbols Model DON’T WRITE.. THINK! Why do you think the atomic symbol for helium is sometimes used to represent an alpha particle?

Alpha Decay Equation

Alpha Decay

Beta Decay

Beta Decay Symbols Model Beta particles are negatively charged particles, that are released from the nucleus. These particles are released in order to turn a neutron, into a proton. Beta particles are faster than alpha particles, but slower than gamma rays. This means that they are more energetic/more dangerous than alpha particles, but less energetic/less dangerous than gamma rays. Beta particles can be stopped by a sheet of aluminum. Symbols Model

Beta Decay Equation

Gamma Decay

Gamma Decay Symbol Model Gamma rays are extremely high energy electromagnetic rays that travel the fastest of all three types of decay. Beta rays do not change the nucleus of an atom, but give off extremely strong, and dangerous radiation It takes a thick wall of lead, or concrete, to stop gamma radiation. Symbol Model

Gamma Decay Equation

Transmutations Transmutations are the changing of one element into another by radioactive decay, nuclear bombardment, or similar processes.

Fission and Fusion-- what’s the difference? Nuclear reactions Fission and Fusion-- what’s the difference?

Before we talk about fission and fusion, we need to talk about the why. Neutrons contribute to nuclear stability. Too many neutrons or protons can cause a nucleus to become unstable and decay. Nuclei with over 83 protons are going to be unstable.

Fission occurs when... a LARGE, somewhat UNSTABLE isotope is split into smaller particles. This splitting occurs due to two situations. Intentional- the nucleus being bombarded with high speed particles (usually neutrons). smaller particles. Spontaneous- a very heavy nucleus splits into smaller particles The result (product) of this process is always two smaller nuclei and energy. Sometimes there is a third product-- extra neutrons

Model of Fission Neutron Smaller nuclei #1 Parent nucleus #2

NOTE: Fusion produces several times more energy than fission! Fusion occurs when... nuclei combine to form heavier nuclei under conditions of extremely pressure and very high temperature The result of this process is a heavier nucleus, a neutron, and a lot of energy. NOTE: Fusion produces several times more energy than fission!

Small nuclei #1 Model of Fusion Small nuclei #2 Neutron Larger nuclei