Chapter 7 Review

How does plastic cling wrap work?

Static charge on wrap induces a charge on what you are wrapping up - attraction

Suppose two identical neutral objects were rubbed together. Is it possible for these objects to gain static charge?

no, they both have the same ability to lose/gain electrons so nothing would change

What are some similarities between protons and electrons?

part of an atom, charged, same size charge

Describe a situation that involves a contact force.

pushing a desk

The word 'static' in static electricity describes what property of the charge?

stationary or not moving

When you touch a charged object with your hand, the object becomes neutral. Why?

the charge is transferred to your body - which is large enough to dissapate the effects of the charge

Compare and contrast insulators and conductors

both have equal numbers of protons and electrons. Conductors allow movement of electrons, Insulators do not.

State the Laws of Static Charge.

Like charges Repel, Opposite charges Attract, Neutral objects are attracted to Charged Objects

What charge does an acetate strip acquire when rubbed?

Negative

What is the part of the atom that is neutral?

Neutron

A positively charged object is brought near another object. The two objects attract. Does this observation prove that the unknown object must be negatively charged?

No - neutral objects would also be attracted

A positively charged object is brought close to another object. If the two objects repel, what is the charge on the second object?

Positive

What is the difference between positively charged objects and negatively charged ones?

Positive - fewer electrons then protons, Negative - more electrons than protons

What is the part of the atom that is positively charged?

Proton

What does it mean to say a conductor is grounded?

Being connected to the earth.

A charge is relocated within a conductor because there is a charged object nearby. What kind of charging process is this?

Charging by Induction

A charge is transferred from one object to another by touching. What kind of charging process is this?

Charging by conduction

What are the differences between charging by conduction and charging by induction?

Conduction - electrons transfer on contact, Induction - no electron transfer, just relocation as the objects only get close to each other - not touching

What is the term for an object that allows free flow of electrons?

Conductor

How are contact forces and action-at-a-distance forces different?

Contact - touching, Action-at-a-dstance - push or pull without contact

What is the unit used for measuring static charge?

Coulomb

What is the part of the atom that is negatively charged?

Electron

Which particles in an atom are transferred when you charge an object?

Electrons

What device detects static charge?

Electroscope

What are some differences between protons and electrons?

Proton is positive, Electron is negative, proton is in the nucleus, electron is around the nucleus

How is it possible for an object to be neutral if it contains millions of electrons?

Protons and Electrons balance each other

The parts of the atom that are in the nucleus.

Protons and Neutrons

Suppose that you are handed an electroscope that has the leaves already spread apart. You now slowly bring a posotive glass rod near the top and the leaves begin to move closer. Why did this happen?

Glass rod is positive, attracting electrons, lessing the electrons (negative charge) in the leaves - moving together

Describe a situation that involves an astion-at-a-distance force.

Gravity, Magnet

An unknown material is rubbed with silk and becomes charged. Explain how you could use a negative acetate strip and a positive glass rod to determine the charge on the unknown material.

If repels - same charge, attract - opposite charge

What is the term for an object that holds charge in one place?

Insulator

State the relationship of the distance between charged objects and their electric force.

further apart - less force, closer together - more force

Explain why a person can get a shock by walking across a carpet and then touching a metal object.

you gain static charge by walking and then the charge flows (jumps, discharges) when you touch metal