1 - lvanessen



Name the three smaller particles that every atom is made up of. State where in the atom these particles are found.

Proton-in nucleus, Neutron-in nucleus, Electron-around the nucleus

1. When is an atom uncharged or neutral?

When the number of protons equals the number of electrons

2. How are solid materials charged?

By rubbing them against some other material

3. What is the overall charge when an atom has more protons than electrons?

Positive

4. What happens to the charge on an atom when:

a. It gains electrons?

It becomes negative

b. When it loses electrons?

It becomes positive

5. What can happen to electrons during friction or rubbing of one object past another?

Electrons can move from one object into another

6. In terms of the motion of electrons, what is the difference between an insulator and a conductor?

Insulators will not let their electrons move inside them but conductors will let electrons move inside them.

7. Explain how an object that is made up of millions of electrons and protons can still be neutral.

As long as the millions of protons have an equal number of millions of electrons, the object will be neutral.

8. What is the purpose of a Van de Graaff generator?

A Van de Graaff generator move electrons from one place to another, causing a large static charge to build up.

9. What are four uses of static electricity?

Static electricity is used in photocopiers, to paint objects, to remove dust particles from air, to stick cling wrap to bowls.

10. What is grounding?

Grounding is connecting an object to the earth or to a much larger object in order to remove a charge or to reduce the electrical force in an object.

11. Why do fuel trucks and airplanes need to be grounded before pumping fuel?

Fuel trucks and planes can get charged and make sparks with objects touching them. Any sparks around them could cause explosions so they must be grounded to make them neutral and unable to produce sparks.

12. The word, “static”, in static electricity describes what property of the charge?

This is charge that does not move – it builds up in a given place.

13. When an acetate strip is charged by rubbing, does it acquire a positive or a negative charge?

It becomes positively charged

14. Draw a diagram of an atom that has three protons, four neutrons, and three electrons.

a. Label the protons, neutrons and electrons.

b. State which particles are neutral, negative or positive

[pic]

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

Electrons are transferred when you charge an object.

16. Using + and – signs, make a sketch of

a. A neutral object

+-+-+-+-

-+-+-+-+

b. A negative object

-+--+--+

+--+--+-

c. A positive object

+-++-++-++

-++-++-++-

17. What is the term for a solid object that holds charges very nearly in one place?

An insulator

18. What is the term for a solid object that allows free electrons to move easily through it?

A conductor

19. What unit is used for measuring static charge?

Coulomb

20. What does it mean to say that a conductor is grounded?

A conductor is attached by means of another conductor to a body much larger than itself, ideally the earth.

21. What is the purpose of an electroscope?

The electroscope is a device to detect charge.

22. What are the similarities between a proton and an electron?

A proton and an electron are both charged.

23. What are the differences between a proton and an electron?

`A proton is 2000 times heavier. A proton is positively charged while an electron is negatively charged.

24. What is the difference between a positively charged object and a negatively charged object?

A positively charged object has more protons than electrons while a negatively charged object has more electrons than protons.

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

Being neutral means that the number of positive charges is equal to the number of negative charges.

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

As a person rubs her/his shoes across a carpet, the person becomes charged because electrons move into or out of the person. When the charged person touches a neutral doorknob, electrons move to make the person more neutral and this movement of electrons is the spark.

27. When you touch a charged object with your hand, the object becomes neutral. Explain what has happened to the charge in this process.

The charge has been removed by electrons moving into or out of the object to the hand.

28. Compare and contrast charged conductors and insulators.

Charged insulators tend to hold their charge because they won’t let it move but charged conductors tend to lose their charge because they allow free movement of any negative charge through them.

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

No because they both have an equal attraction for their electrons.

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