1 / 14

150 likes | 264 Vues

Radioactive Decay. Half Life. What’s In An Atom?. Electrons: Orbit around the nucleus. Negative charge. Nucleus: Has protons of positive charge and neutrons of no charge. A neutron is a proton and an electron stuck together. Net charge is 0. Neutrons.

Télécharger la présentation
## Radioactive Decay

**An Image/Link below is provided (as is) to download presentation**
Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.
Content is provided to you AS IS for your information and personal use only.
Download presentation by click this link.
While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

**Radioactive Decay**Half Life**What’s In An Atom?**Electrons: Orbit around the nucleus. Negative charge. Nucleus: Has protons of positive charge and neutrons of no charge. A neutron is a proton and an electron stuck together. Net charge is 0.**Neutrons**• The force holding the proton and electron together in a neutron is relatively weak. • Sometimes a neutron will break apart, and the proton will be shot out of the nucleus by the repelling force of the other protons. • Neutron Proton + Electron + - + -**Neutrons**• Since these protons are so close to the nucleus when they are “set free”, they leave the atom with incredible velocity. • This is one kind of radiation. • When atoms shoot out these protons, they loose some of their mass (since the protons leaving have mass). +**Half Life**• Def: The amount of time it takes a sample of radioactive material to lose half its mass due to radiation.**Half Life**• Image a 10 kg sample of radioactive “stuff” with a half life of 5 seconds.**Example**• A 1.0 kg sample of U-238 (Naturally occurring Uranium) has a half life of 1.41 X 1017 s, or about 4.4 billion years. How much will remain after 3 half lives? How long will that take?**Example**• A 1.0 kg sample of U-238 (Naturally occurring Uranium) has a half life of 1.41 X 1017 s, or about 4.4 billion years. How much will remain after 3 half lives? How long will that take? • Set up a table:**Example**• A 1.0 kg sample of U-238 (Naturally occurring Uranium) has a half life of 1.41 X 1017 s, or about 4.4 billion years. How much will remain after 3 half lives? How long will that take? • Insert your givens:**Example**• A 1.0 kg sample of U-238 (Naturally occurring Uranium) has a half life of 1.41 X 1017 s, or about 4.4 billion years. How much will remain after 3 half lives? How long will that take? • Fill in the table for correct # of half lives.**Another Example**• Plutonium has a half life of 7.75 x 1011 s. How much will remain of a .10 kg sample after 1.21 x 1013 s?**Another Example**• Plutonium has a half life of 7.75 x 1011 s. How much will remain of a .10 kg sample after 1.21 x 1013 s? • Table and givens:**Another Example**• Plutonium has a half life of 7.75 x 1011 s. How much will remain of a .10 kg sample after 1.21 x 1013 s? • Table and givens:**Further Exploration**• Go to the following website to answer these questions: http://colorado.edu/physics/2000/index.pl • Science Trek → Isotopes and Radioactivity • Balance the following equations: • 7Be4 => 7Li? + ?e1 • 238U? => 234Th90 + ?He2 What is the half life of Neon-19? • What is the half life of Nitrogen-17?

More Related