Oct. 18 – Conductors and Insulators

A lot of people seem to have trouble completing the lab yesterday so I have offered an extension!  You may hand in the lab on Monday without penalty.  Make sure you take the time to complete it well.

I also announced that there will be a QUIZ on Thursday, Oct. 24.

I handed out a couple of worksheets to give you more practice for the quiz.

Handouts: 

• Electrostatic Activity
• Electrons on the Move (contains some solutions!)

Here are some solutions for the electrostatic activity:

Electrons have moved from the acetate rod onto the cotton cloth.

Electrons have moved from the electroscope into the rod.  The electroscope has an overall positive charge and the leaves repel.

I also went over a question from the homework on Tuesday.  Page 477 #6.

#6. Describe how electrons move when a positively charged object is grounded.

When a positively charged object is grounded, electrons move from the ground into the object.  The object is then neutral.

Next we started a new topic:

Conductors and Insulators

Learning Goals: Understand the difference between conductors and insulators.

Success Criteria: You can identify a material as a conductor or insulator.  You can describe some applications of conductors and insulators.

Here are the definitions:

• Conductors:  materials that allow the movement of electrons.
• Insulators: materials that inhibit the movement of electrons.

Section: 11.4, P. 480, list of common conductors and insulators.

All wires use a collection of conductors (copper) and insulators (plastic) to allow electricity to move and to protect people from being shocked.

Power lines use a combination of conductors and insulators to carry electricity to houses and to avoid losing it into the ground.

Here's a video on how laser printers work.  More details can be found in your textbook on page 481-482.

Homework: Complete the Lab and worksheets.