Worksheet: Properties of Electric Charge

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In this worksheet, we will practice converting between the SI unit of charge, the coulomb (C), and the number of electrons that this corresponds to.

Q1:

To start a car engine, the car’s battery moves electrons through the starter motor. How many coulombs of charge are moved?

Q2:

Static electric charges are commonly measured in microcoulombs (µC) and in nanocoulombs (nC).

How many electrons are required to produce a charge of nC?

A electrons
B electrons
C electrons
D electrons
E electrons

How many electrons must be removed from an initially neutral object for the object to have a net charge of µC?

A electrons
B electrons
C electrons
D electrons
E electrons

Q3:

If electrons move through a pocket calculator during a full day’s operation, how many coulombs of charge move through it?

Q4:

In an electric storm, a lightning bolt transfers electrons between some clouds and the ground. The total charge of these electrons is 65.0 C. How many electrons are transferred?

Q5:

A copper penny with a mass of 4.8 g is given a net positive charge of C. To determine the change in the number of electrons in the penny during the charging process, use a value of 63.5 g/mol for the atomic mass of copper and a value of 29 for the atomic number of copper.

How many more protons than electrons are there in the atoms of the penny?

What is the ratio of the total number of electrons in the penny before the charging process to the number of electrons removed from the penny during the charging process?

Q6:

An amoeba contains protons and has a net positive charge of 0.400 pC. What is the ratio of protons to electrons in the amoeba?