Chemistry Brooks 1st

Today students finished Chapter 4 Review and started a worksheet finding the atomic mass.

HOMEWORK: IS DUE BEFORE 7:30... I repeat due before 7:30. You must turn in your atomic mass worksheet before 7:30 on Thursday. If it is late, he is taking 25 points off. No if's and's or buts.

FINDING THE ATOMIC MASS

1. Finding the Relative Abundance:

          Change the Percent Abundance to relative abundance (get rid of the percent) 

          Move the decimal two places to the left for each isotope

2. Finding the Atomic Mass: 

          Multiply the exact mass by the relative abundance and write it on the line.

          Do that for all three isotopes (28, 29, 30)

3. Finding the Average Atomic Mass: 

          Add all three relative abundances together

4. Finding the Element: 

         Look at your periodic table and look for the average atomic mass that you got

        Once you find the element then write down the atomic number