“Do Now” for 10/13/09

“Do Now” for 10/13/09What kinds of changes do these words indicate? Chemical or physical?

Boil Vaporize CrushBurn Grind FermentRot Explode OxidizeC

PC

CC

PPP C

Get your lab notebook from the cabinet when you are done! Open to the page for “Exploding Stomach”

Announcements for 10/13• Pay your $10 lab fees in 225A! Show

me the receipt by 10/24 and receive a HW pass worth one assignment from the textbook.

• Binders should be brought every day! We will take time to organize them Fri after the quiz.

• New HW posted online & on the cabinet.

What do you remember about Moaning Magda?• Loved eating• Training for an eating competition• Read that a French woman trained her

stomach to expand by eating baking soda after a big meal.

• She did the same…and DIED!

• Fill in the heading on the page in your LN• Experiment title: Exploding Stomach• Continue on the page you began last week.

How can we make a model to test this claim?

• What could we use for a stomach?

• What can we use to simulate stomach acid?

• How could we simulate digestion?

• What kinds of data can we collect?

Scientists might not always be able to recreate the conditions that they are testing exactly, due to safety/ethical/cost concerns. Keeping that in mind, think about the following:

Based on costs/safety/ethical issues, here is what we will do:

• What could we use for a stomach?• Small Ziplock bag

• What can we use to simulate stomach acid?• An acid that is close to stomach acid - HCl

• How could we simulate digestion?• Break up food before putting it in the bag

(chewing), squish the contents of the bag with the food and acid (digestion)

• What kinds of data can we collect?• Record qualitative observations- change in

color/temperature/change in products or reactants

Safety• You MUST wear the following at all times until

instructed to take them off from your teacher:– Goggles– Gloves– Apron

• We will be using 1 M HCl (1 molar Hydrochloric Acid), the same acid in your stomach that digests food. – If any comes in contact with your skin, rinse it under

water and inform your teacher immediately!!

Copy this into your lab notebooks

Observation Chemical Change (C)Physical Change (P)

Follow the blue sheet for the lab procedure and clean-up procedures.Summary Questions (answer in Lab NB)1. Why couldn’t you make quantitative

observations in this lab?2. After this investigation, do you find the story

about Magda’s stomach to be believable? Why or why not?

3. Scientists typically detest the word “prove”. Explain why they may feel this way after doing the investigation we just did.

When you are done, tear out carbon copy and turn it in to the HW bin & neatly put away your NB.

“Do Now” 10/14/09 – Copy onto half of a sheet of paper. Also, get the 2 graphic organizers out of your folder from last week.Date: 10/14/09 Topic/Question: How does the common cold work?What I Know

(Think of at least 3 things – fill this in now!!)

What I Want to Know

(Think of at least 2 things - fill this in now!)

What I Learned

(Fill this in during the podcast!)

New questions I have: (Fill in after) Where I can find out: (Fill in after)

Review of Graphic Organizers• Get your graphic organizers and write in

any information that they may be missing. – Remember – these will be great to use for

studying!!

•Have a definite shape•Have a definite volume

Molecules are held close together and there is very little movement between them.

•When placed in a container: might not conform to shape•When heated: expands, but only slightly•Can it be compressed? Doesn’t happen due to molecules being tightly packed

Examples:

•Have an indefinite shape•Have a definite volume

Atoms and molecules have more space between them than a solid does, but less than a gas (ie. It is more “fluid”.)

•When placed in a container: will take the shape of the container, though may not fill the container•When heated: tend to expand•Can it be compressed? can happen, but requires an extreme amount of pressure

Examples:

•Have an indefinite shape•Have an indefinite volume

Molecules are moving in random patterns with varying amounts of distance between the particles.

•When placed in a container: if the container is closed, will expand to fill the entire container

•When heated: will expand, molecules move around more rapidly

•Can it be compressed? Very easily compressed due to LARGE amount of space between molecules

Examples:

At 100°C, water becomes water vapor, a gas. Molecules can move randomly over large distances.

Below 0°C, water solidifies to become ice. In the solid state, water molecules are held together in a rigid structure.

Between 0°C and 100 °C, water is a liquid. In the liquid state, water molecules are close together, but can move about freely.

Plasma is by far the most common form of matter. Plasma in the stars and in the tenuous space between them makes up over 99% of the visible universe and perhaps most of that which is not visible. Plasma radiation within the Princeton

Tokamak during operation.

Plasma temperatures and densities range from relatively cool and light (like aurora) to very hot and dense (like the central core of a star). Ordinary solids, liquids, and gases are both electrically neutral and too cool or dense to be in a plasma state.

X-ray view of Sun from Yohkoh, ISAS and NASA

(right)

Star formation in the Eagle NebulaSpace Telescope Science Institute, NASA (left)

Change in matterChemical• New substance (product)

has different properties / composition from initial ones (reactants)

• Indicators a chemical change took place:– Formation of a Gas– Formation of a Precipitate– Change in Odor– Change in Color– Change in Temperature

Physical• New substance has same

composition as initial substance.

• Phase changes (solid-liquid-gas) are physical changes.– Temperature and pressure

affect melting pts. and boiling pts. of a substance.

– The water cycle is an example of a substance undergoing phase changes.

Examples of ChangeChemical Physical

Exploding StomachDebreifing1. What observations did your group make?

Did you see a physical or chemical change?2. Why couldn’t you make quantitative

observations in this lab?3. After this investigation, do you find the story

about Magda’s stomach to be believable? Why or why not?

4. Scientists typically detest the word “prove”. Explain why they may feel this way after doing the investigation we just did.

“Do Now” for 10/15• Respond to the following on your green

“Do Now” sheet.– What is the difference between an observation

and an inference?– Come up with 2 examples of each about Ms.

Perry =)

• Observation: Something that can be made with only the five senses.

• Inference: Something that involves a decision being made about something you observe. (What you think/feel/guess)

Announcements for 10/15• Homework due tomorrow!• Quiz tomorrow on Chapter 3…all topics

covered this week and last week are fair game – STUDY!!

• Study session today after school, 3:00-around 4:30 or so, here in 365.

• Turn in your “Do Now” sheets today!• You absolutely NEED to bring your binder

tomorrow!!! We will be organizing it and you will be getting it stamped!

If your name appears below, you owe: $96 or your Biology book to the bookroom.• Salmeron, Joshua• Mombela, Francisco• Batie, Alexandria• Vasquez, Maria• Fuentes, Elizabeth• Ballesteros, Jaime

• Hilario, Alexis• Acosta, Bryan• Sanlate, Javier• Jimenez, Michael

Take all issues up with the bookroom during your lunch period. All I have is a list of names. NO you MAY NOT go now.

Brain Pop!

Pay attention to the following points:1.What does that Law of Conservation of Mass

state?2.What is a reactant?3.What is a product?4.Who is considered the discoverer of the Law of

Conservation on Mass?

Substances can neither be created or destroyedSubstances at the beginning of a rxn.

Substances at the end of a rxn.

Antoine Lavoisier

Classifying Elements, Compounds, and Mixtures.• What do you remember about classification from

Biology? What was it used for?• So what do you need for today?

– 1 set of sealed petri dishes• DO NOT OPEN THE DISHES!!

– Colored pencils• Send 1 person from your table to grab materials

and WAIT for further instruction!

What to do first…• 1. Sort the dishes into 2 groups based on

similarities in the contents of the dishes.– If there are disagreements w/in your group,

CALMLY discuss your reasoning until a consensus is reached.

2. One member from each table will be called on to present AND explain your sorting criteria.- Basically say why/how you sorted it the way you did.

3. How might a scientist’s background knowledge influence their process of inquiry and interpretations of data?

The 2 groups for today: mixtures and pure substances• How many types of matter are in a

mixture?

• How is a mixture different from a pure substance?

• How is a mixture made?

• How can a mixture be separated?

More than 1

Has more than one type of molecule or element (pure substance).

By combining 2 or more pure substances.

By physical or mechanical means: filtration, Distillation, Chromatography, etc.

Now…• Send one member from your table to

grab copies of the handout.– 1 copy of the lab handout per 2 people at your

table. Yes, both copies need to be filled out.• Tables of 5 = 1 group of 3, 1 group of 2• Tables of 3 = 1 group of 2, 1 group of 1• Due at the end of the period or tomorrow

w/ HW! So get to work!!• Work on this while you are doing the

activity!

Sort you dishes into mixtures and pure substances!• If you think you had already done this, then

double check and make sure none are misplaced.

• Once you think you have completed this, raise your hand and have Ms. Perry check you work.

• Next, take your non-mixture (pure substances) group, and split that into 2 new groups: elements and compounds.

Explain and defend your sorting!• Why did you sort the sub-groups for the non-

mixtures the way that you did?

• What do you think the definition of an element is?

• What do you think the definition of a compound is?

A substance that contains only 1 type of atom and CANNOT be broken down into simpler substances by chemical or physical means.

A chemical combination of 2 or more elements.

You should have:

Elements R B Gn2

Compounds BGn2P PGn R4Gn

Mixtures RGn + Gn2

R + P + Gn2

B + R BGn2P + PGn

For the remainder of class:• Send one member from your table to grab

copies of the handout.– 1 copy of the lab handout per 2 people at your table.

Yes, both copies need to be filled out.• Tables of 5 = 1 group of 3, 1 group of 2• Tables of 3 = 1 group of 2, 1 group of 1• Due at the end of the period or tomorrow w/ HW!

So get to work!!• TURN IN YOUR “DO NOW” SHEETS

BEFORE YOU LEAVE!!!!• Please return all supplies to where they

were borrowed from.