1 / 11

Reminders & Daily Schedule

Reminders & Daily Schedule. Element Quiz #2 tomorrow Atomic Structure Test Friday Review Isotope/Different Element Worksheet Remind 101 Isotope Abundance/Average Atomic Mass Notes Isotope Practice Packet. Isotopes:. Average Atomic Mass & Abundance. Average Atomic Mass.

grady-lopez
Télécharger la présentation

Reminders & Daily Schedule

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. Reminders & Daily Schedule • Element Quiz #2 tomorrow • Atomic Structure Test Friday • Review Isotope/Different Element Worksheet • Remind 101 • Isotope Abundance/Average Atomic Mass Notes • Isotope Practice Packet

  2. Isotopes: Average Atomic Mass & Abundance

  3. Average Atomic Mass • The decimal number on periodic table • Weighted average of all isotopes of an element • Depends on percent (relative) abundance and mass of each isotope • Measured in “atomic mass units” (amu)

  4. Example • Element X has two isotopes • #1: • Mass=6 amu • Relative Abundance= 7.5% • #2 • Mass=7 amu • Relative Abundance=92.5% • What element is it?

  5. To solve example 1 Average atomic mass= [(mass #1)x(abundance #1)] + [(mass #2)x(abundance #2)] (6 x .075) + (7 x .925)= 0.45 + 6.475= 6.925 amu Closest to ? Lithium 6.94

  6. Finding Percent Abundance There are two stable isotopes of Chlorine: Chlorine-35 (which weighs 34.97 amu) and Chlorine-37 (which weighs 36.97 amu). If the relative atomic mass of Chlorine is 35.45 amu, what is the percent abundance of each isotope?

  7. Chlorine-35 (which weighs 34.97 amu) &Chlorine-37 (which weighs 36.97 amu). X • Cl-35= ? % • Cl-37= ? % Y ? • Having 2 variables would be much harder. • We want to express Cl-37 abundance using X .6 & .4 .8 & .2

  8. Chlorine-35 (which weighs 34.97 amu) & Chlorine-37 (which weighs 36.97 amu). Chlorine relative atomic mass 35.45 amu. • Cl-35 = 34.97 amu • Cl-37 = 36.97 amu X • Cl-35= ? % • Cl-37= ? % 1-X 35.45 34.97 36.97 X 1-X (34.97X) + (36.97)-(36.97X) = 35.45 -2.00X + 36.97 = 35.45 -2.00X = -1.52 2.00X = 1.52 X= 1.52/2.00 X = 0.76

  9. Chlorine-35 (which weighs 34.97 amu) & Chlorine-37 (which weighs 36.97 amu). Chlorine relative atomic mass 35.45 amu. • Cl-35 = X = .76 = 76% • Cl-37 = (1-X) = (1-.76) = .24 = 24%

  10. Isotope Practice Packet • Turn in if finished today—if not it is homework due at the beginning of class tomorrow • Don’t forget to sign up for and tell your parents about remind 101

More Related