Week 2 Term 2 2024 History of Models of the Atom

Homework

Models of the Atom & Radioactivity

• Act 15A, p.173-176 Models of the Atom and Radioactivity
• Ex 5A, p. 151-155 Models of the Atom
• Ex 5B, p.160-171 Radioactivity

Models of the Atom

History of the Atom

Models of the Atom Timeline

Discovery of the Electron: Cathode Ray Tube Experiment

Discovery of the Nucleus: Rutherford's Gold Foil Experiment

Charge of an Electron: Millikan's Oil Drop Experiment

Atomic Structure: Discovery of the Neutron

Parts of the Atom

Isotopes

Isotopes are versions of an atom or an element that have the same number of protons, but different numbers of neutrons

What are Isotopes?

Radioactive Decay

Alpha, Beta & Gamma Radiation

• Alpha particles are emitted by a larger nucleus that has too many Protons
• Beta particles are emitted by a nucleus that has too many Neutrons
• Gamma photons are emitted by a nucleus that has too much Energy (is in an exited state)

• PhET Alpha Decay app can be found here
• PhET Beta Decay app can be found here

Alpha Decay

Beta Decay

Radiation

Types of Radiation

Stable and Unstable Nuclei | Radioactivity | Physics | FuseSchool

Is radiation dangerous?

The Most Radioactive Places on Earth

Millisieverts and Radiation - Sixty Symbols

Half life | Radioactivity | Physics | FuseSchool

Half Life Calculations

Not all your Atoms are Stardust