Happy FRIDAY! 11/30/2012

DO NOW!1. Are most elements on the periodic

table metals, nonmetals, or metalloids?

2. Why are metals commonly used for cookware?

3. Plastic is an insulator. Explain what this means.

4. What does ductile mean?

Create a SMALL T-chart under your Do Now and write down your

observations

Tearing Paper Burning Paper

LEQ #5• What is the difference between a physical and

chemical change?• Create another T-chart underneath. (Take up

the whole page)

• Tearing paper and Burning paper?

Physical Change Chemical Change

Physical Change (NOTES)

• A change that does NOT change the identity of the substance

• ex: –Tearing paper –Melting ice, Boiling water and Freezing

water (change in state or phase)

Chemical Change (NOTES)

• Change in appearance AND chemical make-up -- a NEW substance is formed.

• Irreversible • A chemical reaction occurs.• Ex:

–Burning paper–Digesting Food

Chemical Change (NOTES) Signs of a Chemical Change :

– Color change– Light and Heat is produced– A gas forms (bubbles) – Precipitate forms

• A solid forms from a chemical reaction that takes place in a solution

Brainpop Video

• Write down at least TWO examples of:• Physical change• Chemical Change

In your T-Chart

Hypothesis

• I think that the difference between a physical change and a chemical change is….

• Think - Pair - Share

Hot Question!

Which is an example of a physical change?A. BoilingB. BurningC. RottingD. Rusting

Experiment

• Tell if each example is a chemical change or a physical change.

• Be ready to explain why…Ms. K will randomly pick a team member to explain for the point.

• Add the correct answer to your T-chart in your notebook.

Melting Ice

Chopping Wood

Mixing Salt and Water

Breaking Glass

Burning Wood

Melting Iron

Melting Ice Cream on a hot day

Digesting an apple

Boiling Water

Cooking an egg

Mixing Peas and Carrots

Bicycle rusting

LAB TIME!• Perform each station of the lab (I will lead you in

the first station).• Lab:

– Follow the procedure carefully!!!– Make observations of the change that is occurring– Is this an example of a physical change or a chemical

change?– Explain how you know.

Data Collection

• Discuss your answers with another group…• Did you both get the same conclusions?• Why or why not?• Debate (respectfully)… who was right? Why?

Data Analysis (NOTES)How can you tell the difference between a chemical

and physical change?

• Signs of a Chemical Change–Light and heat is produced–A gas forms–Color change–Precipitate forms

• A solid forms from a chemical reaction that takes place in a solution

Add Examples to your T-Chart

• Salt water boiling• Vinegar and baking soda combining

What about a Mixture? Compound?

Add to your T-chart

Your turn!

• Read one through 10 and decide if it is a physical change (P) or Chemical Change (C)

• The next blank you must explain why? What sign did you see of a chemical change

• You have 7 minutes!

Answer LEQ on back of EXIT TICKET

• Day 1: (Hint: there are 4 signs…)

• Ms. K mixes 2 substances and passes around the flask for students to observe. She tells them a chemical reaction (change) has taken place. How do the students know?

Day 2 LEQ 9Chemical Reactions

• Homework: Chemistry questions due TODAY• # 23 should be C (Boron is the only metalloid) • Do Now: add these words Physical Change – draw a picture Chemical change – draw a picture Participate – draw a picture • Chemical reaction • Reactant • Product• Coefficient• Subscript

HOT Qs1. Which is only a

physical change? souring or milk

melting of iceburning of oil

rusting of iron

2.Which process involves a chemical change? Photosynthesis

freezing water boiling water

melting ice

3. In the making an omelet, which process involves a chemical change?

melting butter frying eggs chopping onions stirring eggs

Chemical Reactions

• Watch the video and watch for REACTIONS–Are they chemical or physical changes

do you think?

• http://www.youtube.com/watch?v=90FR8m-zEH4

So… What is a Reaction?Give me some examples from the

video and life…• a response to something

NOTES

• Chemical reaction-when two or more substances interact and a chemical change occurs– Ex. Rust, when Iron (Fe) combines with Oxygen

(O) in the air– NOT an ex. When water (H2O) evaporates (still

H2O)• Reactant + Reactant Product

– Example: Carbon + Oxygen Carbon Dioxide

Reaction in a Bag!

• Turn in your notebooks to “Signs of a Chemical Change” from yesterday. Be on the lookout to see which of these signs occur in our experiment.

• Combine: steel wool, Yeast and hydrogen peroxide

• What happened? How did you know?

1. Pour the baking soda into the Ziploc2. Put the steel wool into the Ziploc3. Pour your hydrogen peroxide (or is it

vinegar?) into the bag, then QUICKLY zip it up!

4. Shake it like a Polaroid picture.5. Fill out the chart in your notebook and

answer the question with your group.

Hot Question!What type of change has occurred when a

statue changes from it’s original color due to acid rain?

A.The statue has been painted B.Physical changeC.Physical weathering D.Chemical change

Testable Question

• How can we represent chemical reactions?

• Brainpop video

NOTES

• Chemical Equations: how scientists represent chemical reactions

6 CO2 + 6 H2O C6H12O6 + 6 O2

NOTES

6 CO2 + 6 H2O C6H12O6 + 6 O2

ReactantsProducts

Chemical Reaction Coefficient

Subscript

NOTES• Reactants: substances that take part

in a chemical reaction

• Chemical Reaction: process by which new substance is formed

• Products: substances made during a chemical reaction

NOTES

• Coefficient: # of molecules of a compound in a chemical reaction

• Subscript: # of atoms of an element in a compound

Experiment2 H202 2 H20 + O2

2 (H202) 2 (H20) + O2

1.Reactants? 2.Products?3.How many molecules of H20 are in the products?4.How many atoms of Hydrogen are in H202?5.How many atoms of Hydrogen are in the Reactants?

Experiment (Notes)C3H8 + 5 O2 4 H2O + 3 CO2

C3H8 + 5 (O2 ) 4 (H2O) + 3 (CO2 )

1.Reactants? 2.Products?3.How many molecules of H20 are in the products?4.How many atoms of Hydrogen are in C3H8?5.How many atoms of Hydrogen are in the Reactants?

Experiment4Al + 3 O2 2 Al2O3

4(A)l + 3 (O2 ) 2 (Al2O3 )

1.Reactants? 2.Products?3.How many molecules of Al203 are in the products?4.How many atoms of Oxygen are in O2?5.How many atoms of Oxygen are in the Reactants?

Experiment

6 CO2 + 6 H2O C6H12O6 + 6 O2

1.Reactants? 2.Products?3.How many molecules of C02 are in the reactants?4.How many atoms of Hydrogen are in H20?5.How many atoms of Hydrogen are in the Reactants?

What in the world is a precipitate?

• http://www.youtube.com/watch?v=8RmVwz2fNGc (shorter)

• OR• http://www.youtube.com/watch?v=JAeOP2Mf

rDY&feature=related (longer)

Finding the main idea and supporting details!

(20 min. 4 min/paragraph)

• Read the article about reaction rates.• For each paragraph, write down the main idea

and 2 supporting details• 1 reader and 1 recorder• Reader reads aloud• Recorder writes down the main idea and

supporting details• Switch for each paragraph

Factors that affect the RATE of a chemical change (NOTES)

• Rate—how quickly something happens

Factors that affect the RATE of chemical change (NOTES)

• Temperature• Surface area• Concentration

HOT QWhich factors will increase solubility of a solute dissolving in a solvent?

A.Decrease temperature and surface areaB.Decrease temperature and increase surface areaC.Increase temperature and surface area D.Increase temperature and decrease surface area

Ms. Honeycutt will place an alka seltzer in a film canister with:

1. Water 2. Hot water 3. Tablets 4. Crushed Tablet

Students will time how long it took for the reaction to take place

Data Collection

• Record data in the table below:Trial Time

1(water)

2 (hot water)

3 (2 tablets)

4 (crushed tablet)

Reaction Rates Race!

• Answer the conclusion questions about reaction rates.

• It gets harder as you answer more questions• If you get stuck, use your article as your

solution station (it has all the answers!)

Answer the LEQ

• Day 2: How could Ms. Honeycutt have increased the rate of the reaction?