Apologia Chemistry: Precision

We finally finished the Density lab and began Accuracy and Precision. (This lab also teaches these concepts.)  I use an IPS lab which employs a Solo cup, ruler, and sponge.  The kids drop wet sponges into a Solo cup 30 times from a known distance and record the distance from the cup.  If the sponge lands in the cup the measure is 0; if the sponge lands outside the cup, the students measure (with a ruler) the distance the sponge lands from the cup.  Really.  The kids like this lab.  I have them calculate the mean, median, and mode for the 30 measures they record in a data table.

Here are pre-lab questions:
1. What is an accurate measurement in this experiment?
2. Where should the dropped sponges be measured from?
3. Should there be any regulations on how the student on the chair should stand? (Decide if you'll permit them to stand on a chair.)
4. What unit of measure should the class use to measure the dropped sponges? (cm or mm)

Post-Lab questions:
1. What was your most accurate measurement?  Why was it the most accurate?
2. Were your measurements precise?  Explain.
3. Can just one measurement be considered precise?  Accurate?  Explain.
4. Can measurements be precise, but NOT accurate?  Explain.
5.  Compare the mean, median, and mode.  Are they similar or different?
6.  Evaluate your procedure.  Was there enough detail?  What would you change?
7.  Did the data table you constructed fit the data you collected.

Conclusion.
Differentiate between accuracy and precision

Apologia Chemistry: Kool-aid check up, Density of Bowling Ball

Today was Bowling for Density or Will a Bowling Ball Float?  The answer is maybe.  League bowling balls have a maximum weight of 16 lbs.  A bowling ball less than 12 lbs will float and greater than 12 lbs will sink.  The density of water (add ice) is 1.0 g/mL.  We checked the recipes for the Kool-aid Lab, and Vanishing Volume, a discrepant event.  Next class, we’ll complete and debrief all of these labs, answering questions to understand the purpose.  The point is to understand measures, convert units, and calculations, all Module 1.

Apologia Chemistry: Graphing Calc 101 and Kool-aid Lab

The kids were asking about their graphing calculators so I decided to introduce a lesson for half the class.  When I teach TI 83/84, I bring a my TI ViewScreen, overhead, TI 84 graphing calculator, and a bag of TI 83 calculators.  We also use emulators and apps for iPad.  I post a TI  84 poster to show kids where the buttons are located.  When I taught in public schools, the math departments had suitcases with graphing calculators, overheads, and TI ViewScreens.  Ask the local high school to see if a teacher is willing to give your kids graphing lessons.  We learn how to enter and analyze data.  Once you learn how to graph and how to do regressions, you're set.  The TI 83, 84, and TINspire are similar.  Today, we just learned how to enter data in STAT.

The second half is the Kool-aid lab.  I ordered new plastic cyclinders, Kool-aid, and extra didgital scales.  The kids have to determine how much Kool-aid, sugar, and water to make a five ounce cup of Kool-aid.  The idea is to first convert the 2 quart, 1 cup, 1 package recipe to mL and grams.  FYI, there is about 150 grams in one cup of sugar.  One fluid ounce is roughly 30 mL.  Some of the kids just measured the amount of water the cup held in mL using the graduated cyclinder.  This activity takes 45 minutes.  My husband had one group weigh the Kool-aid.  Guess what?  The actual mass of Kool-aid powder varies from the mass listed on the package.  I've never verified the mass before.  The measures will be around 0.2 grams of Kool-aid, 10-15 grams of sugar, and 100-140 mL.  The results depend on how precisely the kids convert or round, the amount of water they use in a 5 oz. cup, whether they use one or two cups of sugar or one or two packages of Kool-aid in their recipes.  But this will give you a ball park estimate.

Apologia Chemistry: Accuracy and Precision.

This is an excellent lab requiring a ruler, plastic cup, and sponges.  You'll want to print these b/c I scanned them upside down.  My copy had stains.  But the lab is that good!  I have the kids design it.  They decide the height to drop it, etc.  I have the kids do 30 trials and record the mean, median, and mode.

Apologia Chemistry: Build basic equipment

I'm constantly reminded that many students do not have basic lab equipment or have large families with tight budgets. The Science Notebook has tips for creating and calibrating liquid measuring devices.  Try to locate a graduated cylinder--even on loan to calibrate your glassware or bottles.  Here are instructions to construct a scale.  A penny made before 1982 has a mass of three grams.  Pennies minted after 1982 have a mass of 2.5 grams.  (1982 pennies vary as the mints changed over.).  Nickels have a mass of five grams.  Coins can serve as weights for your scale.  We use craft sticks to mix and inexpensive plastic palettes as reaction plates.  Walmart sells inexpensive thermometers you can use for many experiments and can calibrate.

Apologia Chemistry: Periodic Table Test and Density or Measurement Lab

Today was the first time the kids took their periodic table tests.  They have to achieve 90% or retake the test until they achieve 90%.  I give them blank copies of the Periodic Table and expect them to know 1-50, Pt, Au, Hg, and Pb.  After the quiz, the kids started the Measurement Lab.  We measured the volume (directly and by displacement) of several objects: metal cubes, glass marbles, metal cylinders,  acrylic blocks, wood blocks, etc.  The kids created data tables of the objects, their mass, volume, density, and percent error.   Here is the volume of geometric objects,  the density of common objects, and direction to calculate percent error.

1. Review the formulas for density, volume of a sphere, rectangle, square, and cylinder.
2. Remind the kids that density= Mass/volume
3. Check that they know how to measure with a digital scale (tare or zero and use a weigh paper) and measure volume with the meniscus.
4. Create a Data Table:
Object              Mass           Volume         Density        Percent Error

5.  Plan for the lab to take at least one hour.  Really.

Apologia Chemistry: Day One

Day One lasts two or three weeks.  Yesterday, the second class session, we checked on the Elements Cards, graphing calculators and emulators, reviewed lab equipment, Claim, Evidence, Reasoning or CER, and taught the kids to create Concept Maps on paper using Measures from Module 1.  The kids are reading Module 1 for Tuesday.  I had hopes of watching the lab safety video; the computer at the library lacks speakers.  Next class, Tuesday, we'll look at Concept Map software, watch the safety film, sign the safety contracts, and do a lab.  Here's hoping for a good year!

Picture Perfect Science

NSTA has an interesting series called, Picture Perfect Science, which uses trade books as vehicles for inquiry-based science.  Pretty cool!  Ask the librarian to see if you can get a copy to examine.

Apologia Chemistry Begins

Today we started Chemistry with two activities: The Checks Lab Activity and The Cube Activities.  (The cubes are located after the article.). My class is 'inquiry-based', which uses data to drive discussions.  We also covered some administrivia.  Our class is using Google Classroom as a tool to house resources and keep records.

NSTA Review: 'Who Made My Lunch?'

Librarians, looking for a series to support National School Lunch week?  'Who Made My Lunch?' by Bridget Heos and illustrated by Stephanie Fizer Coleman is ideal.  This six book series includes all the components of a typical child's lunch: peanut butter, jelly, wheat bread, cheese, ice cream, and chocolate.  The six titles are 'From Milk to Ice Cream', 'From Milk to Cheese', 'From Cocoa Beans to Chocolate', 'From Grapes to Jelly', 'From Peanuts to Peanut Butter', and 'From Wheat to Bread'.  Few children grow up on farms.  Instead children are disconnected from the origins of the food from the grocery store.  What offers more appeal than chocolate bars and ice cream or a classic PB& J sandwich?  The series is intended for the early elementary grades, K-3.  The text is clear without condescension.  For example, in 'From Wheat to Bread', the authors explains, " The wheat sprouts quickly.  But this is winter wheat.  During the cold months, it goes dormant.  That's sort of like taking a nap."  (p.6).  In 'From Peanuts to Peanut Butter', Heos includes interesting details, "At the peanut butter factory, you'll roast the peanuts in a hot oven.  The tray moves up and down so that the peanuts shake while they bake.  This way, they cook evenly." (p.15). At the end of each title is a map displaying where the grapes, peanuts, cocoa beans, etc is grown.  (p.23). On the last page (p.24) are brief glossaries, websites, and bibliographies.  The websites, while brief, are germane.  In the Chocolate book is a link to Fair Trade information and Peanuts includes a site about peanut and tree nut allergies.  The Grapes, Wheat,and Peanuts books could serve as springboards for class discussions about plant growth and cultivation before a science lesson planting seeds.  Any of these titles dovetail with nutrition lessons.  I'm confident children will find these books engaging.  The 'Who Made My Lunch?' Series would make an excellent addition to any library or classroom.