Radioactive elements 4

1. Radioactive Elements Foundation Science 4 Class Code SC22102

2. Radioactivity Radioactive decay – when the nucleus of an atom gives off energy or particles. Three types of decay: 1) Alpha ( α ) decay – gives off protons and neutrons Nucleus of an atom Particles

3. Radioactivity Radioactive decay – when the nucleus of an atom gives off particles. Three types of decay: 1) Alpha ( α ) decay – gives off protons and neutrons 2) Beta ( β ) decay – gives off an electron

4. Radioactivity Radioactive decay – when the nucleus of an atom gives off particles. Three types of decay: 1) Alpha ( α ) decay – gives off protons and neutrons 2) Beta ( β ) decay – gives off an electron 3) Gamma ( γ ) decay – gives off electromagnetic waves

5. So, Radiation can be energy or a particle Alpha ( α ) decay Beta ( β ) decay Gamma ( γ ) decay Is bottom or top alpha decay? Beta decay? Gamma decay?

6. Differences Thin material can stop most alpha ( α ) and b eta ( β ) decay. Gamma ( γ ) decay can only be stopped by thick metals such as lead

7. Differences Thin material can stop most alpha ( α ) and b eta ( β ) decay. Gamma ( γ ) decay can only be stopped by thick metals such as lead

8. Radioactive Elements have large atomic numbers The more protons, the more unstable the atoms tend to be Atomic numbers above 83 are radioactive

9. Isotopes Isotopes of an element have the same number of protons, but different numbers of neutrons. So, helium (He) has 2 protons . Isotopes of Helium all have 2 protons and 4 or 6 neutrons. Some isotopes are unstable, and radioactive.

10. Isotopes

11. Symbols for Radioactivity Radioactive Material Present

12. Geiger Counters Geiger counters measure radiation When alpha, beta or gamma radiation hits the sensor, it “clicks”

13. Geiger Counter How stuff works geiger video

14. Answer in Notebook What are the three kinds of radioactive decay? What kind of decay can only be stopped by a heavy metal like lead ( Pb )? What kind of decay gives off electrons? What is the only type of decay that gives off energy, and not particles? What is used to measure if the radiation level somewhere is safe for humans? In your own words, what is an isotope? What kind of radiation is this?? Why do you think lead ( Pb ) is so good at stopping radiation?