1. I have 8 protons, 8 neutrons, and 10 electrons.
Who am I?
I have 8 protons, 8 neutrons, and 10 electrons.

2. Ions
Atoms that have a positive or negative charge from gaining or losing electrons.
Cation – ion with a positive charge; loses electrons
Ex: Na+1 and Ca+2
Anion – ion with a negative charge; gains electrons
Ex: Cl-1 and O-2

3. Mg
Magnesium 12
23.98

4. Mg
Magnesium 12
23.98 Mg
Magnesium 12
24.98 Mg
Magnesium 12
25.98

5. Mg Mg Mg 12 12 12 Magnesium 23.98 Magnesium 24.98 Magnesium 25.98
What is an isotope?

6. 1 H
Hydrogen
1.01

7. How are the atomic masses calculated on the periodic table?
Percent Abundance

8. Hydrogen (1.01 amu) Carbon (12.01 amu) Isotope Atomic Mass
Natural Abundance
H-1
1.0078
99.985
H-2
2.0141
0.015
Hydrogen
(1.01 amu)
Isotope
Atomic Mass
Natural Abundance
C-12
12.000
98.89
C-13
13.003
1.11
Carbon
(12.01 amu)

9. Percent Abundance - Candium
Candy
# in bag
% Abundance
M&M’s
Skittles
Reese’s Pieces
Total
𝑷𝒆𝒓𝒄𝒆𝒏𝒕 𝑨𝒃𝒖𝒏𝒅𝒂𝒏𝒄𝒆 % = # 𝑖𝑛 𝑝𝑎𝑐𝑘𝑎𝑔𝑒 𝑡𝑜𝑡𝑎𝑙 # 𝑜𝑓 𝑐𝑎𝑛𝑑𝑦 𝑝𝑖𝑒𝑐𝑒𝑠 𝑖𝑛 𝑏𝑎𝑔 𝑥 100

10. 𝑨𝒕𝒐𝒎𝒊𝒄 𝑴𝒂𝒔𝒔= % 𝑎𝑏𝑢𝑛𝑑𝑎𝑛𝑐𝑒 𝑜𝑓 𝑖𝑠𝑜𝑡𝑜𝑝𝑒 1 𝑥 𝑚𝑎𝑠𝑠 𝑜𝑓 𝑖𝑠𝑜𝑡𝑜𝑝𝑒 1
Candy
% Abundance
Mass (of one piece)
M&M’s
Skittles
Reese’s Pieces
𝑨𝒕𝒐𝒎𝒊𝒄 𝑴𝒂𝒔𝒔= % 𝑎𝑏𝑢𝑛𝑑𝑎𝑛𝑐𝑒 𝑜𝑓 𝑖𝑠𝑜𝑡𝑜𝑝𝑒 1 𝑥 𝑚𝑎𝑠𝑠 𝑜𝑓 𝑖𝑠𝑜𝑡𝑜𝑝𝑒 1
+ % 𝑎𝑏𝑢𝑛𝑑𝑎𝑛𝑐𝑒 𝑜𝑓 𝑖𝑠𝑜𝑡𝑜𝑝𝑒 2 𝑥 𝑚𝑎𝑠𝑠 𝑜𝑓 𝑖𝑠𝑜𝑡𝑜𝑝𝑒 2 +…

11. Copper-63 has a percent abundance of 69% and Copper-65 has a percent abundance of 31%. Calculate the average atomic mass of Copper.

12. Bromine-79 has a percent abundance of 50
Bromine-79 has a percent abundance of 50.69% and Bromine-81 has a percent abundance of 49.31%. Calculate the average atomic mass of Bromine.

13. Calculate the average atomic mass of the following element:
25Y (11%), 32Y (39%), 29Y (22%), 30Y (28%)