1. Charge (q) Comes in + and – Is conserved total charge remains constant Is quantized elementary charge, e, is charge on 1 electron or 1 proton e = 1.602  10 -19 Coulombs LIKE charges REPEL and OPPOSITE charges ATTRACT

2. Coulomb’s Law The force between 2 charges depends on the product of the charges divided by the distance squared: F = kq 1 q 2 /d 2 k = 8.99  10 9 N m 2 / C 2 q 1, q 2 are charges (C) d is distance between the charges (m) F is force (N)

3. F = kq 1 q 2 /d 2 If you double one charge - the force will double (larger charges have greater force) If you double the distance the force will reduce to ¼ (farther away the force decreases greatly)

4. Electric Fields By definition, the are “LINES OF FORCE” Some important facts: An electric field is a vector Always is in the direction that a POSITIVE “test” charge would move The amount of force PER “test” charge If you placed a 2 nd positive charge (test charge), near the positive charge shown above, it would move AWAY. If you placed that same charge near the negative charge shown above it would move TOWARDS.

5. Why use fields?  Forces exist only when two or more particles are present.  Fields exist even if no force is present.  The field of one particle only can be calculated.

6. For any electric field  F = Eq  F: Force in N  E: Field in N/C  q: Charge in C

7.  V = Ed Electrical Potential  V: change in electrical potential (V) E: Constant electric field strength (N/m or V/m) d: distance moved (m) Equal and opposite charges on two parallel plates create a uniform field in the space between them.

8. Electrical Potential Energy  U = q  V  U: change in electrical potential energy (J) q: charge moved (C)  V: potential difference (V)

9. Charging and Discharging Charge by friction “BIONIC is the first-ever ionic formula mascara. The primary ingredient in BIONIC is a chain molecule with a positive charge. The friction caused by sweeping the mascara brush across lashes causes a negative charge. Since opposites attract, the positively charged formula adheres to the negatively charged lashes for a dramatic effect that lasts all day.”BIONIC