# Worksheet: Charging by Induction

In this worksheet, we will practice determining the net charge resulting from unequal amounts of positive and negative charges acquired by induction.

Q1:

Suppose a speck of dust in an electrostatic precipitator has protons in it and has a net charge of nC. How many electrons does the speck of dust contain? The magnitude of the charge of protons and of electrons is C.

• A
• B
• C
• D
• E

Q2:

Determine how many coulombs of positive charge are contained in a lump of pure plutonium with a mass of 4.00 kg. Use a value of 244 g/mol for the atomic mass of plutonium and recall that the plutonium has an atomic number of 94.

• A C
• B C
• C C
• D C
• E C

Q3:

A copper atom has 29 protons and a neutral ball of copper has one electron per proton. Copper has an atomic mass of 63.5 unified atomic mass units. A unified atomic mass units is equivalent to g.

How many electrons would be contained in a neutral copper ball with a mass of 50.0 g?

• A
• B
• C
• D
• E

A copper ball with a mass of 50.0 g has a net charge of +2.00 µC. What percent of the electrons in the copper ball have been removed?

• A
• B
• C
• D
• E

Q4:

A copper penny of mass 2.500 g is given a net charge of C.

The charge of an electron is C.

How many excess electrons are on the penny?

• A e
• B e
• C e
• D e
• E e

By what percent do the excess electrons change the mass of the penny?

• A
• B
• C
• D
• E