HappyFRIDAY! 11/30/2012DO NOW! • Are most elements on the periodic table metals, nonmetals, or metalloids? • Why are metals commonly used for cookware? • Plastic is an insulator. Explain what this means. • What does ductile mean?
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 (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? • Boiling • Burning • Rotting • Rusting
Experiment • Tell if each example is a chemical change or a physical change. • Be ready to explain why…Ms.Kwill randomly pick a team member to explain for the point. • Add the correct answer to your T-chart in your notebook.
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 9 Chemical 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 Qs • 3. In the making an omelet, which process involves a chemical change? • melting butter • frying eggs • chopping onions • stirring eggs 1. Which is only a physical change? souring or milk melting of ice burning of oil rusting of iron 2.Which process involves a chemical change? Photosynthesis freezing water boiling water melting ice
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?
Pour the baking soda into the Ziploc • Put the steel wool into the Ziploc • Pour your hydrogen peroxide (or is it vinegar?) into the bag, then QUICKLY zip it up! • Shake it like a Polaroid picture. • 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? • The statue has been painted • Physical change • Physical weathering • 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 Reactants Products 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
Experiment 2 H202 2 H20 + O2 2 (H202) 2 (H20) + O2 • Reactants? • Products? • How many molecules of H20 are in the products? • How many atoms of Hydrogen are in H202? • 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 ) • Reactants? • Products? • How many molecules of H20 are in the products? • How many atoms of Hydrogen are in C3H8? • How many atoms of Hydrogen are in the Reactants?
Experiment 4Al + 3 O2 2 Al2O3 4(A)l + 3 (O2 ) 2 (Al2O3 ) • Reactants? • Products? • How many molecules of Al203 are in the products? • How many atoms of Oxygen are in O2? • How many atoms of Oxygen are in the Reactants?
Experiment 6 CO2 + 6 H2O C6H12O6 + 6 O2 • Reactants? • Products? • How many molecules of C02 are in the reactants? • How many atoms of Hydrogen are in H20? • 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=JAeOP2MfrDY&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 Q Which factors will increase solubility of a solute dissolving in a solvent? • Decrease temperature and surface area • Decrease temperature and increase surface area • Increase temperature and surface area • Increase temperature and decrease surface area