1. Activity 22: Environmental Impact of Computers Warm up: what different materials make up a computer?

2. Activity 22: Environmental Impact of Computers Please open your books to page B51.

3. Materials in a Typical Computer

4. Waste Products from Manufacturing Selected Computer Components

5. Activity 22 Notes The circuit board produces a lot more waste than what it weighs. It weighs 2 kg, but produces 39 kg of waste. A circuit board is primarily made of copper, the most easily recycled material.

6. Activity 23: Producing Circuit Boards Please turn to page B54.

7. Activity 23: Producing Circuit Boards So what is a circuit board? –Basically, it is the brain of a computer, phone, etc. –Transfers electricity to each operating part of a computer through a series of copper paths. Etching- the process used to create the copper paths on the circuit board.

8. Activity 23: Producing Circuit Boards Good circuit board designs don’t just transfer energy from one side to another, but transfer energy to multiple parts of a circuit board along the way.

9. Activity 23: Producing Circuit Boards Circuit-Board Manufacturing- –There are several different methods of producing a circuit board, which is an essential component of a computer, cell phone, etc. –Additive process- copper is added to a board in a specific pattern –Subtractive process- copper is removed from a board, leaving the desired path of copper.

10. Activity 23: Producing Circuit Boards Today, we are completing Part A: Designing and Etching a Circuit Board (pages B55-B56) With your group, read the procedure carefully and following the instructions. When you are finished with your circuit board, bring it to me for etching. Write your initials on the back of your board! After that, read Part C.

11. Balancing Chemical Equations Law of Conservation of Mass- mass cannot be created or destroyed. Reactants (left side of an equation) must be the same amount as the products (right side of an equation)

12. Balancing Chemical Equations Coefficient- number before an element or compound in an equation; can be changed when balancing chemical equations –Must be a whole number Note: by balancing a chemical equation, you are not changing the reaction, you are just determining how much of each material was present during a reaction.

13. Balancing Chemical Equations Steps to balancing a chemical equation: ___K+ ___Br 2  ___KBr 1.Count how many of each element are present in both the products and reactants. 2.Add a coefficient in attempts to balance the equation. 3.Recount your products and reactants to make sure each side is equal

14. Tonight’s Homework Read Part C of Activity 23 (pages B56-B58) Complete “Activity 24 Pre Lab Work” in OneNote. We will be discussing it next time we meet so be prepared!