Electroscopes

Essential Questions for the Electroscopes Lesson: How do charges behave when they are under the influence of a charged rod? What are the parts of an electroscope? How does an electroscope operate? What is another name for charge shift? What is the difference between a charge shift and a charge transfer? What is the difference between charging by induction & charging by conduction? How is an electroscope charged by induction?

Neutral objects are attracted to charged objects... - + + + + + + + + + + + + + Electrons shift...

Neutral objects are attracted to charged objects... + - + + + + + + + + + + + + Electrons shift because... Opposite charges attract.

Neutral objects are attracted to charged objects... - + + + + + + + + + + + + + Electrons shift because... Opposite charges attract.

Neutral objects are attracted to charged objects... - + - - - - - - - - - - - - - Electrons shift because... Opposite charges attract.

Neutral objects are attracted to charged objects... + - - - - - - - - - - - - - - Electrons shift because... Opposite charges attract.

The object is now polarized with charge. + - - - - - - - - - - - - - -

Dial Electroscope Uncharged Charged

Leaf Electroscope Uncharged Charged

INDUCTION + + + + + + + + + + Neutral Electroscope

INDUCTION Electrons shift toward the positively charged object... e- + + + + + + + + + + e- e- Electrons shift toward the positively charged object...

INDUCTION - + + + + + + + + + + + + Charged Electroscope

Neutral Electroscope

INDUCTION - - - - - - - - - - - Neutral Electroscope

INDUCTION Electrons shift away from the negatively charged object... - - - - - - - - - - ------ e- e- Electrons shift away from the negatively charged object...

INDUCTION + - - - - - - - - - - - - - Charged Electroscope

Neutral Electroscope

CONDUCTION e- e- Electrons transfer on the electroscope... - - - - - - - - - - - e- e-

- - - CONDUCTION Electrons transfer on the electroscope... - - - - - - - - - - - - Placing a residual charge on the electroscope... - -

Negatively Charged Electroscope - - -

CONDUCTION e- e- Electrons transfer out of the electroscope... + + + + + + + + + + e- e-

+ + + CONDUCTION Electrons transfer out of the electroscope... + + + + + + + + + + + Placing a residual charge on the electroscope... + +

Positively Charged Electroscope + + +

RESIDUAL CHARGE BY INDUCTION + + + + + + + + + + +

RESIDUAL CHARGE BY INDUCTION + + + + + + + + + + - + + First, electrons shift ...

RESIDUAL CHARGE BY INDUCTION + + + + + + + + + + - + + Second, with the charged rod still nearby, the electroscope is grounded ...

RESIDUAL CHARGE BY INDUCTION + + + + + + + + + + e- - + + allowing electrons to enter (transfer in) ...

RESIDUAL CHARGE BY INDUCTION + + + + + + + + + + e- - e- + + and move toward the positive leaves.

RESIDUAL CHARGE BY INDUCTION + + + + + + + + + + e- - e- + + Now the electroscope has excess electrons ...

RESIDUAL CHARGE BY INDUCTION - - - and is negatively charged.

Using a negatively charged rod near the electroscope and grounding the electroscope results in... A positive residual charge.

Check Questions for the Electroscopes Lesson: How do charges behave when they are under the influence of a charged rod? What are the parts of an electroscope? How does an electroscope operate? What is another name to describe charge shift? What is the difference between a charge shift and a charge transfer? What is the difference between charging by induction & charging by conduction? How is an electroscope charged by induction?

You have completed the Electroscopes Lesson. Captain Einstein says “Good Job!”