1 / 4

Aim: What is a half life of an element?

Aim: What is a half life of an element?. 212 Po 4 He +____. Do Now: Solve the following in your notes:. 142 Pm +____ 142 Nd. Half Life. The half-life is the amount of time it takes for half of the atoms in a sample to decay.

slade-mcbride
Download Presentation

Aim: What is a half life of an element?

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

Presentation Transcript

  1. Aim: What is a half life of an element? 212Po 4He +____ Do Now: Solve the following in your notes: 142Pm +____ 142Nd

  2. Half Life • The half-life is the amount of time it takes for half of the atoms in a sample to decay. • The half-life for a given isotope is always the same .

  3. Practice Problems • 1. The half-life of Th-227 is 18.2 day. How many days are required for 0.70 of a given • sample to decay? • 2. The half-life of Rn-222 is 3.823 day. What was the original mass of a sample of this • isotope if 0.0500 g remains after 7.646 day? • Try this yourself::::: • 3. The half-life of Pa-234 is 6.75 hr. How much (what fraction) of a sample of this • isotope remains after 20.25 hr?

  4. Homework # 5 1. Write nuclear equations for the following processes: • a. Ra-226 decays by α-emission. • b. The result of the β-decay of an isotope is Mg-22. • 2. Carbon-14 has a half-life of 5730 y. How much of a 144 g sample of carbon-14 will • remain after 1.719 × 104y? • 3. If the half-life of uranium-235 is 7.04 × 108 y and 12.5 g of uranium-235 remain after • 2.82 × 109 y, how much of the radioactive isotope was in the original sample?

More Related