1. What day is it again? The subatomic particle that has a positive charge is called the ______________? The subatomic particle that is able to move to create a positive charge is called the _____________ ? A proton has a charge of ______Coulombs. One proton is (+/-) one fundamental or elementary charge. The # of Coulombs of one elementary charge is located on line __on the front of the Reference Table

2. Objectives The fact that charge comes from protons and electrons means that there must only be discrete amounts charge available to charged objects. Electrons are the only things that move, so even when something is positively charged we talk about an electron deficiency. Homework – Finish Worksheet/ Short C L Test/Quiz Next Thursday !

3. An object has three excess electrons. –What is its “elementary charge”? –What is its charge in coulombs? -3e q = -3e x (1.6 x 10 -19 C)/e = -4.8 x 10 -19 C Example #1

4. An object has 75 protons and 65 electrons –What is its “elementary charge”? –What is its charge in coulombs? +10 e q = +10e x (1.6 x 10 -19 C)/e = +16 x 10 -19 C Example #2

5. Law of Conservation of Charge The total amount of charge in a closed system remains constant – charge is not created or destroyed, it only moves from one object to another Charge “moves” as a result of ELECTRON movement ONLY!!!

6. A metal sphere with two excess electrons touches a neutral metal sphere and then taken away. –What do you predict the charge on each sphere will be after they make contact? –What is the total charge on both spheres after they come in contact? -1e or -1.6 x 10 -19 C -2e or -3.2 x 10 -19 C The TOTAL CHARGE remains the SAME!!! Example #3

7. End of 5.1.1 - PRACTICE