Friday, February 21, 2020

Science Kits: Which types are the best values?

Good Will and eBay have eScience, Bob Jones, Apologia, and Labpaq kits as listings frequently.  I like eScience and Labpaq kits.  Some lab kits are better buys than others.  I look at a wide variety of kits; my husband and I teach Chemistry, Biology, and Physics classes.  Last summer I taught Human Biology; this summer we are planning a science camp for elementary-aged children.  So, I can use a wide variety of equipment.

I usually do not bid or buy Physics kits.  These kits usually have styrofoam cups, a glass stir rod, mini compasses, a protractor, etc.  This physics kit has a spring scale, digital scale, and tuning fork along with marbles, bolts, a ruler, straws, etc.  However, too often these kits are priced at $50 or more.  No thank you.  I bid and bought a QSL Physics Kit from Good Will two years ago.  I paid $30 with shipping.  Good Will and eBay offer QSL Chemistry, Biology, and Physics kits occasionally.  My price limit is still $35 with shipping.  But the QSL kits are uniformly excellent kits.

The Labpaq kits can be good deals.  This listing is a good example; the kit has a thermometer, digital scale, dissection kit, plastic labware, test tubes, test tube brush, rack, and test tube holder.  This Chem Kit is another good choice; the lab kit has a digital scale, thermometer, multi-meter, sterno, and a molecular modeling kit.  I always discount the chemicals.  Who knows how hold they are?

BTW, the QSL kits are usually designed for high school aged science students.  The eScience and Labpaq kits are designed for college students.  More and more of the nonmajor or introductory science classes are available online, especially through community colleges.  Some students manage to pass the class without doing any of the labs or experiments in the kits.  That is why there are a variety of kits available online, seemingly unused.  These lab kits can be great deals.  I promise to keep you posted.

Science Kit Again

Good Will has an eScience Kit listing that is a decent deal.  The kit has a plastic cylinder, several beakers, a glass thermometer, pipettes, and a few test tubes.  I cannot tell if the safety box has goggles or not.  The shipping weights are accurate.  Sometimes Good Will stores inflate the shipping weight increasing the shipping costs dramatically.  If you are looking for basic science equipment, this kit is priced fairly.  Don’t over bid.  Another kit will be available soon.

Thursday, February 20, 2020

Apologia Chemistry: Solubility and Module 11

Today the Chem class redid the Solubility Rules Lab.  I was concerned about cross contamination.  I do teach before, during, and after labs.  For example, we reviewed solubility before resuming lab.  I also asked the kids to identify the types of chemical reactions are involved in precipitate reactions. (Double replacement reactions.)  Before lab, I asked them to identify the solubility rules they already understood.  For example, nitrate compounds are soluble.  Period.  Sodium and potassium compounds are soluble.  Period.  Most silver and lead compounds are insoluble---EXCEPT silver nitrate, silver acetate, lead nitrate, and lead acetate.

During lab, I usually just prompt them and answer questions. For example, the silver nitrate and lithium chloride did not produce a precipitate.  I had the kids add powdered lithium chloride to the silver nitrate to observe the precipitate.   After lab, we summarized their findings.  What are the Solubility Rules?  I make a point of emphasizing that the rules are based on lab observations--just like their lab observations.

After lab the class did reaction predictions for these precipitate reactions--double replacement reactions.  I reviewed the symbols for precipitate reactions.  We did one more set of reaction predictions and identified the solid precipitates.  I also went over the solubility rules lab rubric.

Solubility Rules Lab
Title: Solubility Rules Lab Report

Background:  What does solubility mean?  What is a precipitate? Define soluble and insoluble.  Use the Apologia Chemistry textbook.

Materials: List all of the materials, such as disposable transfer pipettes or wood stir sticks.  The students may summarize the reactants. For example, over one dozen different soluble compounds may be included in the materials instead of listing each compound, such as sodium phosphate solution.

Procedures: The procedures are summarized.  The various reactants, such as barium chloride and potassium sulfate are combined in reaction plates.  The student observes each reaction to note precipitates.

Data Chart:  The data tables my be hand-drawn or electronic versions.

Reaction: Predict, write, and balance one of the precipitate reactions observed during lab.  

Discussion: Identify sources of error.

Citation or Attribution: Use MLA formating to cite the textbook.

Wednesday, February 19, 2020

Science Kits Again

Here  is another eScience kit online.  While it has 0.01 shipping, the price is $30.  Look at the contents: food wrap, measuring spoons, a few test tubes, pipettes, glass rod, safety glasses,  and plastic beakers.  In the clear bags are miscellaneous items for specific labs: beans, rubber bands, paper clips, tape, etc. (Here is another eScience kit at Good Will.  Look at the photos of the contents.  There is an image of typical items in the small plastic bags.  BTW this kit is $15; however, look at the shipping!  Ouch!).  Note I am discounting the chemicals.  How old are they?  Are these chemicals I use in my labs?  Who knows?  Yes, I am tempted by eScience lab kits, too.  I’m giving this one a hard pass.  I have plenty of test tubes, plastic beakers, and safety glasses.  Keep your eye out for a Labpaq or eScience kit with a digital scale or mortar and pestle instead.

Tuesday, February 18, 2020

Apologia Chemistry: Metal Reactivity and Solubility Lab

The kids are working through the two labs: metal reactivity and solubility lab.  The class completed the metal reactivity and did several additional labs to determine which metals are more reactive and can displace other metals.  Yes, I could have given them the notes.  Instead, the kids combine the metals and determine which metals are more reactive by adding, say, zinc to magnesium sulfate and magnesium to zinc sulfate.  The metal reactivity series is based on observations.  The kids did additional reactions to confirm the metal reactivity series: zinc and magnesium sulfate, magnesium and zinc sulfate, iron and zinc sulfate, zinc and iron chloride, aluminum and zinc sulfate, etc.  Initially, the kids observed the magnesium and zinc are very reactive; the aluminum and iron appeared less reactive.  Aluminum is quite reactive.  It appears to react more slowly.  So, we put 0.4 g of aluminum with 0.2 M copper chloride solution again.  After a bit of discussion, we performed several reactions to see which metals aluminum displaces.  We hammered home the idea that single replacement reactions are based on a metal’s reactivity.

The kids are still working on the solubility rules lab.  Again, I'm having them make observations and draw conclusions from their observations.  I give heavy hints.  For example, the reactants in the lab are all soluble. Another hint is to react silver nitrate and lead nitrate with as many compounds as possible.  We established that nitrate compounds are soluble.  We also discussed the meaning of soluble, insoluble, and precipitate.  I had assumed these definitions would be obvious.  They are NOT.  Here are some pix.

Friday, February 14, 2020

Apologia Science: CBL2

Good Will online has a CBL 2 listing just added. (This is a similar listing on eBay for $30.)  These devices require a TI 83/84 graphing calculator.  The CBL collects the data from sensors or probes and sends the data to the graphing calculator, usually to the STAT lists.  This listing has a thermometer, light probe, and voltage sensor.  So, the sensors alone are useful even if the CBL does not work.  Often, the owners are intimidated by the devices and they remain unused.  Here is a lab manual.  Here is a ‘quick start’ manual.

These devices are NOT hard to use.  There is a link cable which connects the CBL to the TI 83/84 calculator.  Follow these instructions.  Be sure to use the cable link to connect the CBL2 to the Ti 83/84.  You need a TI 83 PLUS or a TI 84 calculator.  The TI 83 plus has apps and can accommodate the Data Mate app.

Yes, I know I push technology for home-schoolers.  Really, I push cost-effective technology to home-schoolers.  The CBLs are good examples of affordable technology.

I went down to the basement classroom to trouble shoot the CBL 2.  (I just bought one from Good Will about two weeks ago.)  Here are excellent instructions to quick-start collecting data on the CBL2 with a graphing calculator.  I took photos.  I will talk to my kids and see if we can set up an afternoon to do some videos.

                                 My set is identical to the current CBL2 listing on Good Will.
                       I used the TI 84 to test the CBL.  You need a TI 83 plus with the Data Mate app.
                                            Here are the contents with the CBL 2 box.
  The probes included with theCBL2 connect to the TI 84 with Easy Data—preloaded on TI 84 with Easylink.

                         This is how the TI 83 calculator connects on a cradle with the CBL2.
                                  Hi    The probe is inserted into the lowest channel available.
                                 The cable link connects between the CBL2 and the Calc.
     You need a TI 83 plus and must download the DataMate app from the web with the USB connector shown on the right. Here is a link to the TI USB connecting cable for TI 83 calcs.
  The TI 84 had Data Mate preloaded.  I followed the directions to collect temperature data from the Quick Start guide from Mighty Grammarian.
                        See?  The data collected in stored in L1 (trials) and L2 (temperature data)

Thursday, February 13, 2020

Apologia Chemistry: Three Labs

The class nearly completed all three labs.   My goal is to complete a minimum of 25 labs.  Next week, we will finish the Solubility Rules lab and debrief all three labs.  Our digital scales are not sensitive enough to determine the difference between the mass of aluminum before and after for the Limiting Reactant lab.  I will review limiting reactants with the kids and predict the theoretical yields together next week.  The second lab was the metal reactivity lab.  The idea is to observe the manner several metals react with copper II chloride solutions.  The difference is distinct.  The only issue was the mossy zinc turns black quickly.  Zinc is more reactive than iron nails.  The kids did not observe the immediate change and thought iron was more reactive than zinc.  The kids are completing the solubility rules lab.  Next time, I need to review the purpose of each lab, discuss the results, and write equations.  We did all of that today.  The problem is the kids just forget.  Below are photos.  I like to include pix because they can be used for the children's digital portfolios.

Wednesday, February 12, 2020

Apologia Chemistry: Review

One suggestion I have for you is to do constant review.   For example, give the kids two reactants and ask them to predict the products, write the formulas, and balance the equation.  This reviews nomenclature and balancing equations.  Then ask them to determine the number of grams of each reactant needed to form five grams of one or both of the products.  As often as possible, write compounds and molecules in words and have the kids write the correct formula.  It's the only way to keep these skills fresh.

Apologia Chemistry: Module 6 and Module 11 Solubility

Tomorrow I am doing at least two labs: Limiting Reactants (Stoichiometry) and Metal Reactivity or Activity Series Lab.  We may be able to do the Precipitates and Solubility Lab.  Why?  The kids took the stoich quiz Tuesday.  The results indicate I need to do more work on the ratio concept.  I want to introduce the idea of limiting reactants, but not belabor the concept.  At the same time, the quiz I gave them yesterday was single reaction predictions.  The reactions were based on metal reactivity.  (Here is an activity series for metals.)  I want the kids to do the lab and revisit the single replacement reactions from yesterday.  Which reactions would take place? 

The kids are also going to make their own solutions of 0.2M copper II chloride dihydrate solution and the solutions for the Precipitates and Solubility Lab. (Here is a chart of the solubility rules.)  I find that if the kids get in the habit of making their own solutions, they gain a good understanding of molarity.  I like to introduce molarity with moles while their minds are on moles.  I will post later this week with an update as to how far we got with the labs.

Tuesday, February 11, 2020

Science Articles

My chemistry posts are redundant this time of year.  We are in the midst of moles and Stoichiometry. So I have been trying to think of other topics until we switch gears in Chemistry and tackle more interesting topics.

Home-schooler often read more than private, public, or parochial students do.  When I taught in private and public schools, the teachers were strongly encouraged to increase the number of reading and writing assignments.  I like ‘lessons in a can’: an article, a short writing exercise with a prompt, and a lab.  One example is Tatoos: Thinking About Tattoos? article or What Chemicals are in Your Tattoo?, Should you get a tattoo writing prompt, and Making Ink Lab.  (I have completed this lab successfully without the gum arabic or acacia.). Before I assign the writing prompt, we do a risk analysis as a class.  A Risk-Benefit Analysis is easy; the class makes a list of the risks and benefits—much like a list of the pros and cons.  Then I ask the kids to weigh the risks versus the benefits.  Do the risks outweigh the benefits or vice versa?  Finally, I ask if they should get a tattoo?

Another good topic is Counterfeit CurrencyCountermeasures (2007) is a good place to start.  This is a good article to use with the strategy, Claim, Evidence, Reasoning, CER.  I ask the kids to identify countermeasures to counterfeit currency.  Do the countermeasures work?  What is the claim?  What evidence supports the claim?  Finally, explain your reasoning.  It is a more thoughtful exercise than writing a paragraph summary. One easy activity is to get out new bills and foreign currency.  Let the kids look at the bills with microscopes—especially digital microscopes which attach to laptops.

The third idea is Fireworks.  What is in fireworks?  Do the Flame Test lab.

Here are recent free issues from ChemMatters.  I’m renewing my print subscription.  I took a year off and miss the issues.  ChemMatters has Videos relating to the monthly topics, too.  The Dec 2019 ChemMatters issue has an article about Vaping.  This article is pretty balanced.  Ask kids to discuss whether flavored e-cigarettes should be banned.  Should the age for all cigarettes be raised from 18 to 21?  Do they think these measures will reduce e-cigarette use?  What are the risks of black market e-cigarette liquids?  No, I do not have an e-cigarette lab.  I am betting kids will write volumes on the topic.

Apologia Science: Materials

Children should come to class prepared.  All types of teachers agree, regardless of the class setting.  I am solution oriented.  I taught class in private and public schools.  Not one class was entirely prepared.  Ever.  At the beginning of the school year, I buy composition notebooks, spiral notebooks, reams of lined paper, graph paper, pencils, etc.  when it is on sale.  I have caddies with both graphing and scientific calculators.  I keep other caddies with markers, staples, high-lighters, tape, rulers, pencils, etc.  In other words, necessary supplies are available.  In this manner, my focus is on teaching.  The kids know where the supplies are located.  I do not waste time reprimanding them for being unprepared.  Yes, I make extra copies of all of the assignments for the same reason.  My husband has extra copies and pencils out on the table for the kids.  He and I know someone will forget something.  I just want to teach.

Science Kits: Which types are the best values?

Good Will  and eBay have eScience, Bob Jones, Apologia, and Labpaq kits as listings frequently.  I like eScience and Labpaq kits.  Some lab...