1. Warm-Up 2/3/14
None!
We are going to take the start of class to put together our notebooks.

2. Atomic Numbers and Masses
Thursday 2/3/14

3. Learning Objective #1
I Can…describe the location, mass, and charge of protons, neutrons, and electrons in an atom.

4. Atomic Number—the number of protons in an atom
Atomic Number—the number of protons in an atom. The number of protons identifies the element!
In a neutral atom, it is also the number of electrons! (Neutral: + and – balance out)

5. Atomic Mass—the sum of the masses of protons and neutrons in the nucleus
Particle
Approximate Mass
Proton 1
Neutron
Electron

6. PROTONS + NEUTRONS = ATOMIC MASS
NEUTRONS = ATOMIC MASS – PROTONS
PROTONS = ATOMIC MASS - NEUTRONS

8. Same thing, different size.

9. Isotopes—atoms of the same element that have different numbers of neutrons
Average Atomic Mass—weighted average mass of an element’s isotopes. (Found on the periodic table)

10. Two main isotopes of Carbon:
Carbon-12 (6 protons, 6 neutrons)
Carbon-14 (6 protons, 8 neutrons)

11. Finding the Missing Particle
Element
Symbol
Atomic #
Protons
Neutrons
Mass #
Ave. Atomic Mass
Boron B 6 C 12
Sodium 11 23

12. Your Job
Complete the Periodic Squares practice worksheet (Left side, pg. 8)
Paste notes on right side, pg. 9