1. Chem Get Atoms WS stamped off if you did not do so last time Today:
Atoms/Isotopes
Average Atomic Mass
Average Atomic Mass Mini-lab
Atoms Quiz Thurs 2/16 (B), Fri 2/17 (A)

2. What is important about the atomic number?
Unique for each element
= # protons in nucleus

3. How do you figure out the number of:
Protons in an atom?
# protons = the atomic number
Electrons in an atom?
# electrons = # protons
FOR NEUTRAL ATOMS, only!
Neutrons in an atom?
# neutrons = mass – # protons

4. What are Isotopes?
Isotopes are different forms of the same element that have a different mass
Isotopes have the same # protons but different # neutrons

5. What are Ions? Ions are atoms that have a positive or negative charge
In an Ion, the number of protons and electrons are not equal

6. Standard Nuclear Notation
Note: for ions, the charge (+ or -) is indicated in the upper right corner

7. What is the ONE THING that determines the identity of an atom?
# of protons (atomic #)

8. Practice

12. 24.305
24.984

13. Average Atomic Mass Complete Candium Lab-turn in
Complete Average Atomic Mass problems