Definition 9.2.1. Charge.
Charge is a physical property of subatomic particles, measured in coulombs (C), that governs how matter interacts with electric and magnetic fields.
Section 9.2 Charge
Electric charge is a fundamental property of matter. Objects that are "charged" can display interesting behaviors when interacting with electric fields that we will explore in this chapter.
Electric charge can be positive or negative. Positive charges are associated with protons, and negative charges are associated with electrons. Protons reside in the nucleus of atoms while electrons "orbit" nuclei. We represent positive charges with the symbol "+" and negative charges with the symbol "-". In examining the behavior of positive and negative charge, we can find that like charges tend to attract while unlike charges repel. Therefore, two electrons will repel each other while a proton and an electron will tend to attract.
Exercises Activities
1.
An atom always has the same number of protons as electrons. What is the total charge on such an atom?
2.
Suppose you have an object with a net charge of exactly 1.0 C. How many more protons than electrons are in this object? Based on this, do you think a net charge of 1.0 C is typical for an everyday object, or is it much larger or smaller than you would expect for an everyday object?
