1. Introduction to Electrostatics

2. Recall: Atomic Structure
Atom
2

3. Recall: Atomic Structure
p+ (+ve charge) and n0 (neutral charge) are
found in the nucleus.
Protons
3

4. Recall: Atomic Structure
Neutrons
4

5. Recall: Atomic Structure
The ONLY time a p+ or n0 leaves the atom is
if the atom is radioactive.
Nucleus
5

6. Recall: Atomic Structure
e- (-ve charge) are found outside the
nucleus. They can move between atoms and
flow freely.
Electrons
6

7. Recall: Atomic Structure
Neutral atoms or objects have equal amounts of
e- and p+.
+-+
-+-+
-+-
7

8. Recall: Atomic Structure
-vely charged atoms or objects have more
e- than p+.
+--+
-+--+-
-+---
8

9. Recall: Atomic Structure
+vely charged atoms or objects have more
p+ than e-.
+++
-++-
9

10. Introduction to Electrostatics
The Greek
philosopher Thales
(600 B.C.) was the first
to record electric
observations when he
rubbed amber with
fur.

11. Introduction to Electrostatics
The amber could
attract small
objects.

12. Introduction to Electrostatics
Materials that attract other materials after
rubbing are charged.
This occurs because electrons move from
one object to another.

13. Introduction to Electrostatics
A negatively charged object has more electrons
than protons (excess e).
+--+
-+--+-
-+---

14. Introduction to Electrostatics
A positively charged object has fewer electrons
than protons (deficit of e ).
+++
-++-

15. Introduction to Electrostatics
A neutral object has an equal number of +ve and -ve
charges.
+-+
-+-+
-+-

16. Introduction to Electrostatics
Static Electricity:
Charges that remain stationary on the surface of an
object ("static" means "not moving").

17. Introduction to Electrostatics
Electrostatics:
The study of static electric charge.

18. 3 Laws of Electric Charges
1) Like charges repel each other.

19. 3 Laws of Electric Charges
2) Opposite charges attract each other.

20. 3 Laws of Electric Charges
3) A charged object will attract a neutral object.

21. 3 Laws of Electric Charges
3 important rules:
i) Objects with like charges repel each other.
ii) Objects with opposite charges attract.
iii) Neutral matter is attracted to charged matter.
Charge Charge Attract or Repel?
+ve +ve Repel
-ve -ve Repel
+ve -ve Attract
Neutral +ve Attract
Neutral -ve Attract
21