ITTY BITTY REACTIONS MathScience Innovation Center 2009

What makes Alka-Seltzer fizz in water?

What do you think caused one lid to pop before the other?

To respond to a question: Wait for polling to open. Select your response. You do not have to turn on your responder, it is ready to go.

Why do scientists use models to study different objects or processes? 1. Process happens too fast or slow naturally 2. The original object is too small or too large 3. The original process is too dangerous 4. All of the above 5. 1 and 3 15

TODAY WE WILL……. Build Models Create Test Calculate

Lets Review Formulas S u r f a c e A r e a Ratios V o l u m e D i m e n s i o n s

What are the dimensions of a cube? 1. Faces 2. Length 3. Edges 4. Width 5. Height 6. All of the above 7. 2, 4, and 5 Height Length Width :15

What is surface area? 1. The amount of space an object takes up 2. What you see 3. The area of all the faces of a three dimensional figure 4. None of the above 5. 2 and 3 15

How could we find the surface area of a cube? 1.Lwh 2.2lw + 2lh + 2wh 3.6s 2 4.½ bh 5.2 and and 4 15

Write down the formula for surface area in your journal.

What is volume? 15 Seconds Remaining 1. The amount of space an object takes up 2. What you see 3. How many edges there are 5. All of the above 6. 2 and 3

How can we calculate the volume of a cube? lwh 2. 2lw + 2lh + 2wh 3.6s 2 4.s and and 4

Write down the formula for volume in your journal.

A scatter plot… 15 1.Shows data frequency 2.Shows relationship between 2 variables 3.Shows relationship of the parts to the whole

The Surface Area of a cube is 24 cm 2. The volume is 48 cm 3 What would be the ratio of the surface area to the volume?

Each group will need: Bag of Blocks Calculators Ruler and Pencil

Calculate the: volume (s 3 ) surface area (6s 2 ) As a group make one large cube using the 64 small cubes. Measure a side to the nearest centimeter. 3 minutesminutes 3 minutesminutes

Length (cm) SAV # of cubes made Total Surface Area Total VolumeSA/V ratio 8 cmlg. med. sm. 1 cm.5 cm Fill out only the boxes in yellow

Length (cm) SAV # of cubes made Total Surface Area Total VolumeSA/V ratio 8 cm384 sq cm 512 cu cm 1 lg. med. sm. 1 cm.5 cm Fill out only the boxes in yellow How do we calculate the total surface area and volume?

Length (cm) SAV # of cubes made Total Surface Area Total VolumeSA/V ratio 8 cm384 sq cm 512 cu cm 1 lg. 384 sq cm 512 cu cm 384/512 =.75 med. sm. 1 cm.5 cm Fill out only the boxes in yellow How do we calculate the total surface area and volume?

SA/V Ratio Length Plot your first point

Deconstructing A Cube

5 minutesminutes Make as many medium (4cm x 4cm x 4cm) cubes as you can using all 64 cubes. Find the surface area and volume for ONE of the medium cubes.

How many medium cubes did your group create? How can your group find the total surface area and total volume using the data just gathered?

Length (cm) SAV # of cubes made Total Surface Area Total VolumeSA/V ratio 8 cm 384cm 2 512cm 3 1 lg. 384cm cm cm med. sm. 1 cm.5 cm Record the information for one medium cube in the boxes.

Length (cm) SAV # of cubes made Total Surface Area Total VolumeSA/V ratio 8 cm 384cm 2 512cm 3 1 lg. 384cm cm cm 96 sq cm 64 cu cm 8 med. sm. 1 cm.5 cm Record the information for all medium cube in the boxes.

Length (cm) SAV # of cubes made Total Surface Area Total VolumeSA/V ratio 8 cm 384cm 2 512cm 3 1 lg. 384cm cm cm 96 sq cm 64 cu cm 8 med. 768cm cm cm sm. 1 cm.5 cm

Find the surface area and volume of one small cube. 5 minutes Calculate the total surface area, total volume, and SA/V ratio. Don’t forget to plot your point.

Please put all 64 cubes and the 4 rulers back into the bag.

LOOKING FOR PATTERNS Length (cm) SAV # of cubes made Total Surface Area Total VolumeSA/V ratio 8 cm 384cm 2 512cm 3 1 lg. 384cm cm cm 96 cm 2 64 cm 3 8 med. 768cm cm cm 24 cm 2 8 cm 3 64 sm.1536 cm cm cm.5 cm

1. Finish the chart 2. Plot the last 2 points 3. Answer questions 1 – 3. 8 minutes INDEPENDENTLY

What happened to the total volume as the cubes got smaller? =

Which size cube had the greatest TOTAL surface area? 1.8 cm 2.4 cm 3.2 cm 4.1 cm cm 10

As the cubes got smaller, the ratio of the surface area to volume ____ 1.Remained the same 2.Increased 3.Decrease 10

SA/V Ratio Length Dependent variable Independent variable

What does this have to do with chemical reactions?

Nanoscale 1 nanometer = one billionth (10 -9 ) meter Red Blood Cell Width = mm = 6,000 nanometers Width = mm = 3 nanometers Width = 0.1 mm = 100,000 nanometers One strand of hair DNA

Itty Bitty Reactions at the Nanoscale

Using what was discovered today, explain why one lid popped quicker than the other lid during the Alka-Seltzer experiment.

Each group needs

ALKA-SELTZER Put goggles on Put film canister in sm. tub Fill film canister to line with water Place lid on canister quickly Start timer and STAND BACK

Clean-Up Procedures WIPE goggle rims EMPTY water DRY canisters, measuring cups, and containers with a paper towel. PUT timer and goggles back into bag. BRING everything to front of room

Goggles must be worn at all times during the final activity. You have ten minutes to complete Experiment and clean up.

Thank you!