Charging by Induction

Today we took up homework questions on p. 482.
Grade 9s learned how to use a negatively charged balloon to induce a non-permanent charge on a stream of water. They also learned how to use a charged object to induce a permanent charge on a neutral object. The big ideas from today's lesson are that:

• charging by conduction produces two object with the same charge
• charging by induction produces two objects with opposite charges

Homework & Reminders:

• Powder Coating research is past due
• Complete questions on p. 489
• Complete the analysis and application sections of Bending Water
• April 2 - Study Hall - We will use some of this time for extra science classes, including review work for next week's test
• April 3 - Good Friday, No school
• April 6 - Easter Monday, No school
• April 7 - Electricity test

Testing for Conductors and Insulators

We began today's lesson reviewing how a metal leaf electroscope works and how we can use a charged balloon to negatively charge the electroscope. Once this was done, students used the negatively charged electroscope to test various materials to determine if they were conductors or insulators.

Homework & Reminders:

• Powder Coating research is past due
• Complete questions on p. 482 past due
• Complete the analysis and application sections of Testing for Conductors and Insulators
• April 2 - Study Hall - We will use some of this time for extra science classes
• April 3 - Good Friday, No school
• April 6 - Easter Monday, No school
• Electricity test week of April 7 - 10

Conductors and Insulators

We used the start of today's class time to take up Wednesday's homework.
In today's lesson, students learned about insulators and conductors, and how laser printers use the Law of Charges to work.

Homework & Reminders:

• Powder Coating research is due Monday, March 30
• Complete questions on p. 482 on conductors and insulators
• April 2 - Study Hall - We will use some of this time for extra science classes
• April 3 - Good Friday, No school
• April 6 - Easter Monday, No school
• Electricity test week of April 7 - 10

Library Trip

Grade 9s had a triple dose of science class today while the Grade 10s were writing their OSSLT.
They started the day by beginning work on an investigation to determine if the Law of Electric Charges can be used to determine the charge on an object.
A little later, we headed out to Meadowvale Library, where students worked on a research project on electrostatics in powder coating. This research paper is due Monday, March 30.
Later in the day, the Grade 9s returned for the regular science class. They used this time to conclude the investigation they began in the morning.

Homework & Reminders:

• Write up of "Predicting Charges" investigation due tomorrow
• Powder Coating research is due Monday, March 30
• Electricity test week of April 7 - 10

Charging by Contact

We took up yesterday's homework questions at the start of today's class. We then discussed charging by friction and conduction. Students performed an activity with tape to help them understand charging by conduction. Their conclusions on this activity is are due tomorrow. We also learned about grounding and how electrostatic forces are used in precipitators.

Homework & Reminders:

• Complete conclusions in Charging by Conduction Activity
• Complete questions on p. 477 of textbook
• Students will be working on a research project on tomorrow's library trip

The Characteristics of Electricity

We began term two with a new unit on electricity. In yesterday's lesson, Grade 9s discovered how much their understanding of the atom from term two's chemistry unit helps them to understand static electric concepts. Students conducted activities to examine the interactions of charged objects with other objects and with a pith ball electroscope. Students were asked to complete their reflections for homework.
Today we continued with static charges. Students learned that the Law of Charges is similar to magnetic force concepts, except we are now dealing with electric forces. Students learned about the interaction between a charged and a neutral object. They are developing an understanding of charge by induction. They conducted an activity to examine the interaction between a charged object and a neutral object. They are asked to complete the conclusions part of the worksheet for homework and submit it tomorrow.
Students also examined a gold leaf electroscope and learned how this device works to detect charge.

Homework & Reminders:

• Complete conclusions in Charging Objects Activity
• Complete questions on p. 471 of textbook
• Return library trip permission form tomorrow
• Tomorrow is Casual Day
• Library trip on Thursday, March 27

Models

Grade 9 students spent today's class finishing up their molecular models worksheets.
Have a wonderful break everyone.

Unit Test

Grade 9s wrote their unit test for the molecules and compounds unit.

Unit Review

Grade 9s worked on a self-quiz on p. 282 & 283 to prepare for the unit test on Thursday, March 5. We took up about half the work. Students are asked to complete the remaining work on their own and to speak to me early on Thursday if they have any queries about the remaining questions. Students who were not able to complete the molecular models assignment may do so after the unit test on Thursday. Model building supplies will be available to do this.

Hydrogen Peroxide

We had our last teaching class of chemistry today. Students learned how molecules break part by studying the example of hydrogen peroxide. Students are reminded that their Molecular Models assignment is due tomorrow. Students will be writing a test on unit 7 on Thursday, March 5.