- 134 Views
- Uploaded on
- Presentation posted in: General

Calculating Average Atomic Mass

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.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Calculating Average Atomic Mass

Unit 9 worksheet 2

- The decimal number on the periodic table
- The weighted average of all the isotopes of an element
- Depends on the percent (relative) abundance and the mass of each isotope
- Measured in “atomic mass units” (amu)

- Given:
- Element X has 2 isotopes
- Mass = 6 amu and percent abundance = 7.5% (0.075)
- Mass = 7 amu and percent abundance = 92.5% (0.925)

Average atomic mass = [(mass) x (abundance)] + [(mass) x (abundance)]

[(6) X (0.075)] + [(7) x (0.925)]

0.45 + 6.475

6.925 amu

On the periodic table, this is closest to Li, atomic number 3.