1. 25.3 – Detecting Radioactivity

2. Radiation detectors
Instruments used to identify ions formed when radiation passes through matter

3. Electroscopes – measure charged particles in the air
Cloud chamber – detects alpha or beta particles by means of a trail of condensed vapor
Bubble chamber – detects radioactive particles by means of a bubble trail in a superheated liquid

4. Geiger Counter Video Clip
Measures radioactivity by producing an electric current when radiation is present
Video Clip

5. Background radiation
Comes from radon gas produced in Earth’s crust, from cosmic rays and from radioactive isotopes in the body

6. In-Class Assignment/Homework
Pg. 800 #1-5
25.3 Reinforcement WKT