Electrostatics

The charge of an electron is 

• positive. 
• negative. 
• Electrons have no charge

Atomic nuclei of almost all elements consist of 

•  protons and neutrons
• protons and electrons.
•  neutrons and electrons.
• only protons.

Two like charges

•  neutralize each other.
• repel each other. 
• must be neutrons. 
• attract each other.

Electrical forces between charges are strongest when the charges are 

• far apart. 
• close together. 
• The electrical force is constant everywhere.

The net charge of a nonionized atom 

• depends only on the number of electrons it has.
• usually cannot be determined. 
• is zero. 
• depends only on the number of protons it has.

To say that electric charge is conserved means that no case has ever been found where 

• the total amount of charge on an object has increased.
• the total charge on an object has changed. 
•  one object has more charge than another object. 
• net charge has been created or destroyed. 

Charge carriers in a metal are electrons rather than protons, because electrons are

•  relatively far from a nucleus. 
• loosely bound.
• lighter.
• none of the above

A conductor differs from an insulator in that a conductor has

• more protons than electrons. 
• none of the above
•  more electrons than protons. 
• more electrons than an insulator. 

A negatively charged rod is brought near a metal can that rests on a wood table. You touch the opposite side of the can momentarily with your finger. The can is then 

• positively charged. 
• negatively charged.
•  charged the same as it was. 
• uncharged.

An electroscope is charged positively, as shown by foil leaves that stand apart. As a negatively charged rod is brought close to the electroscope, the leaves

• spread farther apart.
•  do not move. 
• move closer together