Static electricity Physics test

What are the three subatomic particles in an atom?

Protons, Neutrons, Electrons.

What happens when an atom loses an electron?

It becomes a positively charged ion.

Which charges can move in static electricity?

Only electrons move.

What is the unit of electric charge?

Coulomb (C).

What is the charge of one electron?

-1.6 x 10^-19 C.

Formula for total charge?

Q = n × e (charge = number of electrons × charge of one electron).

What does the law of electric charges state?

Like charges repel, opposite charges attract.

Why do electrons stay in atoms?

Attraction between protons and electrons.

What is the force between charged objects called?

Electric force.

What factors affect electric force?

Amount of charge and distance between charges.

What is an electric field?

The region around a charged object where forces act on other charges.

Why is an atom neutral?

Equal numbers of protons and electrons cancel charges.

How do objects become charged?

By gaining or losing electrons.

Why don’t atoms usually lose protons?

Protons are deep inside the nucleus.

What device detects charge?

An electroscope.

Name the 3 ways objects can be charged.

Friction, conduction, induction.

Describe charging by friction.

Electrons are wiped from one object to another (e.g., cloth & plastic ruler).

Describe charging by conduction.

Electrons move by direct contact between objects.

Describe charging by induction.

Charges rearrange in an object without direct contact.

What does the law of conservation of charge state?

Charges cannot be created or destroyed, only transferred.

What is a conductor? Give examples.

Material where charges move easily (e.g., copper, aluminum, mercury).

What is an insulator? Give examples.

Material where charges cannot move easily (e.g., plastic, rubber, glass, wood, air).

What is static electricity?

Electric charge at rest on an object.

What is electric discharge?

Loss of static electricity as charges move off an object.

Give examples of electric discharge.

Slowly: static on clothes. Quickly: lightning.

Why does lightning strike the highest point?

It provides the shortest path to the ground.

What is a lightning rod?

A metal rod connected to the ground by a wire, used for safety.

What does it mean for an object to be “grounded”?

Connected to Earth by a conductor, allowing charges to flow safely.

Why can Earth absorb charges without damage?

Because it is very large.

How does a lightning rod protect buildings?

Directs charges safely into Earth, preventing damage.