If everything is made of atoms, why is it that skin is flexible and permeable while a cell phone is rigid and waterproof? 1/26/15 Date:1/26/15Topic:Endo vs. ExothermicPage # ___ Answer in journal

Today in Room 315… ADMIT SLIP: If everything is made of molecules, why are things different textures? HW: Write discussion on last page of lab packet (due Wed) CONTENT OBJ: SWBAT explain the relationship between chemical bonds and energy LANG. OBJ: SWBAT write a discussion of their lab report ANNOUNCEMENTS: Likely snow day tomorrow... GET YOUR STUFF DONE (NO EXCUSE!!) AGENDA: Endo vs. Exo Lab Bonding Notes EXIT SLIP: Fill out last page of lab packet Date:1/26/15Topic:Endo vs. ExothermicPage # ___

Endo vs. Exo Lab Today’s lab requires you to use hazardous materials to create dangerous chemical reactions If you show any signs of carelessness, you will be asked to not participate Wear safety goggles at all times. Should you get substances on your skin, wash it off immediately

Endo vs. Exo Lab Lab first  Discussion later Please stay organized and on your game so we can get through everything I would recommend filling out your Materials section as we go through the steps Before you begin, choose your roles (I will choose the Materials Manager)

Procedure Let’s read through the procedure together (cross off step #12) and discuss the roles… Recorder / Timer Materials Manager Temperature Taker (Qualitative) Temperature Taker (Quantitative)

Lab Demo

Lab Protocol Follow each step carefully Work together safely and efficiently Everyone cleans You have 20 minutes… go!

Grab a computer and check your grades. Is there anything that looks strange? Let me know because they close TODAY! 1/30/15 Date:1/30/15Topic:Endo vs. ExothermicPage # ___ Get out your atoms/elements homework to be collected

Today in Room 315… ADMIT SLIP: Check grades HW: Write discussion on last page of lab packet CONTENT OBJ: SWBAT explain the relationship between chemical bonds and energy LANG. OBJ: SWBAT write a discussion of their lab report ANNOUNCEMENTS: Grades close TODAY AGENDA: Endo vs. Exo Lab Review Bonding Notes Endo\Exo Worksheet EXIT SLIP: Fill out last page of lab packet Date:1/30/15Topic:Endo vs. ExothermicPage # ___

Lab Demo* Reactant 1Reactant 2Product Temp Endo/Exo? **Make this chart in your journal- you will need it for homework!** Will come back to this!

Grab a computer and check your grades. Is there anything that looks strange? Let me know because they close TODAY! 1/30/15 Date:1/30/15Topic:Endo vs. ExothermicPage # ___ Get out your atoms/elements homework to be collected

Today in Room 315… ADMIT SLIP: Check grades HW: Write discussion on last page of lab packet CONTENT OBJ: SWBAT explain the relationship between chemical bonds and energy LANG. OBJ: SWBAT write a discussion of their lab report ANNOUNCEMENTS: Grades close TODAY AGENDA: Endo vs. Exo Lab Discussion Bonding Notes Endo/Exo Worksheet EXIT SLIP: Fill out last page of lab packet Date:1/30/15Topic:Endo vs. ExothermicPage # ___

Complete Class Data Chart Open up word document: Endo Exo Lab Table

So… what happened? Why are some reactions cold and some reactions hot?? Why are some objects flexible (skin) while others are hard (cell phone)?? All has to do with…

Atom Organization* Structure and function of matter is determined by: Atom combination (types of atoms) Atom arrangement (placement of atoms) Atom arrangement determined by chemical bonds methane octane

Chemical Bonds* Hold atoms together to form molecules Energy is stored within the structure of a molecule’s bonds and atoms To break a bond = energy added To make a bond = energy released Regardless of bond making and breaking, atoms remain (conservation of matter)

Types of Energy* Ideas? Ideas?HeatLightElectricalSolarNuclearMechanicalChemicalMagnetic

Friction What is it? Ever experienced rug burn? What happens? How does your skin feel? When molecules move, they encounter other molecules and generate friction. Friction produces heat. (Knee + Rug = Friction = Heat)

Thermal Energy Electric current moves through metal coils, causing the metal atoms to move rapidly and get hot Add cold water to a hot pan, what happens?

Chemical Reactions Cause Heat If heat is released = exothermic reaction Exo = out Thermic = heat If heat is absorbed = endothermic reaction Endo = in Thermic = heat

Exothermic Reactions* Molecules present at the beginning Molecules present at the end

Exothermic Rxns* If you can feel the heat, heat has been produced at the reaction is exothermic Examples??

Endothermic Reactions*

Endothermic Rxns* If the end result feels cold, it means your heat was absorbed, and therefore an endothermic reaction occurs Examples??

Lab Packet Turn to the last page of your lab packet and fill in the blanks for the first two questions Then, go back to your table and classify each reaction as endo or exothermic.

Exit Slip Endo vs. Exothermic Reaction Practice (worksheet)