Download Radioactivity Radioactive Decay - Hewlett

Radioactivity
The spontaneous release of radiation from an element.
Nuclear Reactions
• Change the composition of an atoms nucleus.
Isotopes
• Atoms with the same number of protons but different numbers of neutrons.
• Example: Carbon 12 and Carbon 14.
• Unstable isotopes will go through radioactive decay.
Radioactive Decay
Process where particles and energy are released from unstable isotopes.
Geiger Counter
• Used to measure radiation.
Three Types of Radioactive Decay
• Alpha Radiation
• Beta Radiation
• Gamma Radiation
Types of Radioactive Decay
Alpha Decay
•
•
•
•
Produces an alpha particle.
Consists of 2 protons and 2 neutrons
Decreases the atomic number by 2
Decreases the mass number by 4
Think of an alpha particle like a helium nucleus.
226
88 Ra
222
86
Rn
+
4
2
Beta Decay
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•
•
•
Produces a beta particle.
Releases an electron.
Increases the atomic number by 1.
Mass number remains the same.
131
131
53
54
I
Xe
+
0
­1
Gamma Decay
• Usually accompanies alpha and beta decay.
• High energy waves.
Relative Strength of Radiation
Low
• Alpha Radiation is low strength.
Medium •
Beta Radiation is medium strength.
High • Gamma Radiation is high strength.
Summarization of Radiation
Penetration of Radiation