1. Friday October 1, 2015 TO DO RIGHT NOW: 1.Get out your HW and PT 2.Copy words on page 42 3.Update your table of contents HOMEWORK Due Monday- Isotope Worksheet (Use the notes and tutorial video #6) REMINDERS Tutorials are 7:00-7:25 am and 2:40-3:00pm (quick questions only. Get scientific calculator!!! Check grades online! I will finalize before leaving today.

2. Monday October 5, 2015 TO DO RIGHT NOW: 1.Get out your HW and PT 2.Copy words on page 42 3.Update your table of contents HOMEWORK Finish classwork for HW the answer bank is online. REMINDERS Tutorials are 7:00-7:25 am and 2:40-3:00pm (quick questions only. Get scientific calculator!!!

3. 1. I have 22 neutrons and a mass of 40. 2. I have 37 protons and 39 electrons. 3. I have 20 neutrons or 22 neutrons and 19 protons.

4. Write notes on the page across from your timeline

5. ◦ An oxygen atom weighs 2.657 x 10 -22 g. This is difficult to use. ◦ The atomic mass unit (amu) was developed for the purpose of making calculations easier.

6.  1 amu = 1/12 th the mass of a Carbon-12 atom

7.  The weighted average of the mass for all of the isotopes of an element.  Atoms of the same element have different isotopes.

8.  The average atomic mass is a WEIGHTED average of ALL of the isotopes for an element.  The average atomic mass of a sample of an element can be found on the periodic table ◦ Ex.) Zinc = 65.39 amu

9.  The mass of one atom is not exactly the same as the average mass of many ◦ Ex.) 1 atom of Zinc  65.39 amu

11.  (% abundance x mass number isotope 1)  + (% abundance x mass number isotope 2)  + (% abundance x mass number isotope 3)  + etc.  = average atomic mass for the element DO NOT DIVIDE BY ANYTHING! This is not a regular average. Don’t forget to change the percentage to a decimal first!!!

12. Copper has two naturally occurring isotopes: copper-63 (69.17%) and copper-65 (30.83%). Calculate the average atomic mass of copper if the relative masses of the isotope are copper 63 (62.93 amu) and copper-65 (64.93 amu).

13. Cu-63 (0.6917 x 62.93 amu) Cu-65 + (0.3083 x 64.93 amu) 1) Change % to a decimal 2) Line up your info. 3) Use parentheses on calculator if you want to do it all at once without having to write it down for each isotope!

14. Cu-63 (0.6917 x 62.93 amu) Cu-65 + (0.3083 x 64.93 amu) Avg. mass = 63.55 amu