Science for Kids

Factual Questions
21

Well, I was a kid who was successfully taught critical thinking (I think :wink: ). Here’s what I remember, and what I’m trying to do with my own kids.

The one thing I distinctly remember my father said to me was "The people you learn about in history class, like George Washington, Ben Franklin, Galileo, Isaac Newton - you don’t learn about them because they agreed with everything they heard. You don’t hear about them because they memorized stuff in a book. You learned about them because they disagreed. They questioned authority, they questioned ‘knowledge’. Sometimes it got them laughed at, and sometimes it got them into trouble. But they changed the world because they didn’t sit back and just agree with what everyone said. They challenged people and ideas. They had the courage to say ‘I don’t know if you’re right or not, so I’m going to come up with my own conclusion.’ "

As for dealing with my own kids - Personally, I’m a big fan of the Socratic method. I’ll often ask them apparently-easy questions like “Is the earth round or flat?” and then ask them to justify their answers.

A typical conversation is something like:
Me: Is the earth round or flat?
Them: Round!
Me: How do you know?
Them: Umm…hmmm…well, it’s always round on TV
Me: Yeah, but I thought TV was fake.
Them: Not all TV. Movies and stuff.
Me: Well, I’m looking out the window and the earth looks flat to me.
Them: Yeah, but if you see it from space its round!
Me: When have you ever seen it from space?
Them: They’ve got pictures of it from the moon!
Me: Who?
<etc>

It’s a conversation you can have at dinner that doesn’t require too much prep-time or setup. You just toss out a question and let the conversation develop from there. They key (IMO) is not to outright try to teach them anything. Just get them to do the talking.

It’s not much. But I do think it’s teaching them to really give some thought to what they think they know.

22

Cooking is a great trove of chemistry experiments waiting to be done. I think the cookie idea is a great one, and will do very well to explore the scientific method, complete with hypothesis(es) and testable outcomes. The recipe on the back on the chocolate chips will work quite well as the control recipe, and they can vary one ingredient in subsequent batches. Vary the temperature of the oven and the length of baking time, as well. What happens if they melt the butter before mixing, or chill the dough before baking? What gives them crunchy cookies? Chewy? Thin? Fat and fluffy?

It’s a good opportunity to let them design a FLAWED experiment (generally kids will do this by changing more than one variable) and asking them “Well, if you added more sugar and increased the temperature, which thing made a difference in your cookies?” They will quickly realize on their own that changing only one variable at a time will give them more useful results.

Finally, I’d encourage you to let them design their own experiements to find the answers to things *you *don’t know. If you know what the results will be, there is less magic in it for you. You can (unintentionally) radiate a smug condescending tone to them. It can be damn irritating to know dad knows the answer but won’t tell them.

So listen to their questions and encourage them to find out for themselves, rather than having you look it up on the internet together. Alton Brown has answered the cookie chemistry question. BUT DON’T GO READ HIS TRANSCRIPTS! It will be much more fun for all of you to experiment together. Remember, there are no failed experiments, just hypotheses to discard!

My son had fun with trying to make Twinkies go stale. He had heard that adage that Twinkies have a 20 year shelf life or something, and asked me why they don’t go stale. I asked him why he made that assumption, and if he thought he could make a Twinkie go stale. He designed a set of experiments with varied temperature and heat to make Twinkies go stale (but first he had to define “stale” and figure out how to measure that!)

He loves corn starch goo, and spent a weekend [del]playing[/del] experimenting with different combinations of powders (flour, agar, guar gum, sugar, baby powder) and liquids (water, rubbing alcohol, hydrogen peroxide, vinegar, corn syrup) that he found around the house to see if he could make other goos. Was it a stinky mess? Hell yeah! But he learned a lot about the properties of polymers. He might not be able to articulate them, but when he studies them in high school or college, the words will make much more sense because he’s felt them.

He also repeated my 8th grade science project: he tested the absorbency of various brands of diapers for me. We had samples of several brands given to us when the baby was born. He developed an experiment (with some guidance) to test swatches using salt water made to the pH of urine to help me decide which ones we should buy. (Would he have been interested in diapers without a baby sister? Probably not. But this is a good example of taking your ideas from the kids’ environment, rather than giving them arbitrary projects.)

As for your mall experiment: not a bad idea for high school or college. But grade school kids don’t really care about other people enough to care what they think. They’re still too self-centered to find psychology really thrilling.

23

Whynot I say this seriously and not as sarcasm. You must be very proud. The corn starch slime experiments are exactly what I and others are recommending. After being taught to make slime with cornstarch and water, his curiousity led him to ask questions, experiment, and to learn.

Nature’s Call These science modules were in the sixth grade, and in another state. If I could find a copy of the electricity module, I’d shout it from the rooftops. It was probably the best beginner’s course in electricity I’ve ever read. The only program I can remember by name was the economics course. It was incredibly dorky. Sadly, it involved no experiments. But, it went smoothly from how money works (we all agree to accept it), to inflation, to things like trade imbalances. It was titled Willy And The Walnuts.

Earthworm Jim I like it! I agree that it sounds like a great way to teach kids critical thinking, skepticism, and debating skills.

24

I am very proud of him. He’s a bright, inquisitive kid who does horribly in school because he has a language learning difficulty. I like to encourage him to learn things at home to remind him he isn’t dumb.

I am also proud of myself, a bit. I think the most important thing to do in teaching as a parent is to get out of your kids’ way. Where would science be without the serendipitous “opps – Ah hah!” moments that come when you “mess up”? Stop trying to control how they think and guide them to the answers you “know” are right. Stop worrying about the mess being made in the kitchen. Stop trying to teach, and let them learn! (I address these to the general “you”, not to the OP or anyone else in particular.)

We have a few guidelines: no electricity experiments unless they come out of a box and you follow the directions. Mom doesn’t know diddly about voltage and current. No mixing bleach and ammonia. We’ll trust the experts on what happens when you do that. Clean up when you’re done. (Everything he works with so far is available around the house - he hasn’t asked for a chemistry set because he hasn’t exhausted the possibilities he already has!) If he needs help or gets stuck, he asks for it. Usually, I’m just the lab assistant, helping to pour and stir as he instructs. Are some of his experiments utter failures? Of course! Could I have seen it coming and averted the disaster? Of course! But why would I want to do that? He learns much more by falling than he would by being caught.

25

Both of you folks need to pull out a chemistry text.

If you try to electrolysize water in a solution of aqueous NaCl, gaseous hydrogen is produced at the cathode by the reaction:
2H[sub]2[/sub]O (l) + 2e[sup]-[/sup] -----> H[sub]2[/sub] (g) + 2OH[sup]-[/sup] (aq)

There are two competing reactions at the anode:
2H[sub]2[/sub]O (l) -----> O[sub]2/sub + 4H[sup]+[/sup] (aq) + 4e[sup]-[/sup]
-and-
2Cl[sup]-[/sup] (aq) -----> Cl[sub]2[/sub] (g) + 2e[sup]-[/sup]

While the first anode reaction (that produces oxygen gas) is thermodynamically more favorable, if the chloride concentration is reasonably high, the second anode reaction will actually predominate, forming chlorine gas.

Shalmanese, any oxygen gas formed is not going to react with the aqueous sodium ion to form anything, much less hydroxide. However, locally at the cathode hydroxide will be produced, as can be seen above.

csharpmajor, the danger in your experiment is that with a concentrated solution of sodium chloride, you are producing chlorine gas, not oxygen. The sodium is not involved at all. No elemental sodium will be produced; it remains as a spectator ion throughout.

26

I never said anything about hydrogen gas I was just pointing out that the oxygen atoms are going to be still bound as a hydroxyl ion which means that the remaining solution becomes sodium hydroxide.

27

duh, I meant oxygen gas.

28

The best ways to “teach” logic, deduction, hypothesis, experimentation and in short science to kids are to ask questions and to encourage your kids to ask questions. The simple questions like “Why?” “How?” and “What happens if?” are the best and they can be adapted to absolutely any subject that interests your particular children. Concentrate on teaching your children to always observe and process what goes on around them, and the rest will take care of itself.

To salvage your mall experiment, I’d take the whole exercise down to the kid’s level. You think your older child is likely to be interested in statistics. Ok, fine. But lets take Freak-a-nomics to the grade school set. Have your kid ask questions to people from several groups he encounters in his everyday life… friends, classmates, sports teamates, neighbors, people he knows from church/or the religous experience of your choice if any etc. (and it doesn’t matter if individuals overlap and are in more then one group) No more then say 10 content questions (Age, Sex etc. would not be consider content questions, and in most cases your kid can probably fill those data in himself).
Ask your kid in advance to make 5 “guesses” about overall trends in the answers… (perhaps something like “Kids I know from soccer will watch less TV per night then the average” or “On average adults will have more cash in their pockets then kids”) When the data is in, run the numbers and see what falls out. Both you and your kid might be surprised. If the “experiment” is relevent to their everyday life, kids are more likely to be interested.

I’ve done many science demonstrations and experiments with grade school kids… and because these were preplanned, and for large groups of kids (through their schools) I generally tried to at least somewhat tie in to whatever subject the kids were studying at the time… but the best experiments, and the ones the kids retained the longest were the ones that came out of the kids own questions.
Encourage your kids to ask questions, and when they do, try to help them learn the answer for themselves, and not just from a book or from a websearch… these are great tools and certainly shouldn’t be overlooked… but whenever possible try to help your kids find a way to actually test these answers for themselves. Help your kids to see what is and isn’t a good test (only changing one variable at a time, for example) It’s also very important to Let Them Fail - as long as no one is likely to be hurt, failure is a very valuable teaching tool. It’s one thing to tell a child something won’t work, but it has a much greater impact if they try it, and then (if necessary) you help them figure our WHY it didn’t work.

Good luck.

29

I have to strenuously disagree with the bolded statement. (I know you’re just being modest rather than contrary but the point can’t be emphasized enough.) Teaching them to think critically and question assumptions (whether by a Socratic dialog or otherwise) is crucial to science and experimentation and indeed, any intellectual aspect of life. It’s not much of an accomplishment, really, to memorize some trivia and factoids. It’s another–and infinitely more valuable–skill to learn to ask good questions and parse the result to distinguish between fact, opinion, and assumption. The sample conversation you offer is a perfect example; everybody knows the world is round, of course, but how we know it and how we can objectively demonstrate it to others without resorting to argumentum ad verecundiam (an appeal to authority) is indispensible in perpetuating knowledge in opposition to hearsay and superstition.

Someone else mentioned Dick Feynman; I’m currently reading Perfectly Reasonable Deviations From The Beaten Path, a collection of his correspondence over his lifetime. A couple of his letters address the inadequacy of primary school science textbooks he reviewed while on the California State Curriculum Committee, later reworked into a section in “What Do You Care What Other People Think?” (the “Energy makes it go!” non-sequitor). There are a lot of there letters from people–mostly high school or undergraduate students–soliciting advice on what fields to study or are likely to be worthwhile and interesting, to which his constant response is, “Study what you find fascinating, be it physics or otherwise.” I think that’s key to successfully teaching anything; finding a way to connect the material to the students’ interests, and encouraging them pursue their own lines of reasoning and investigation.

There’s one other letter in the book (pgs 289-90) which doesn’t have a direct bearing on the topic at hand, but it’s just such a piercing, aptly self-deprecating comment that I can’t help but include it: Feynman got a letter from an undergraduate named Beulah Cox, complaining that her professor had incorrectly docked her on an exam, based upon a statement in The Feynman Lectures regarding the resultant external charge from a distribution of static charges inside a conductor. Feynman responded,

Your instructor was right not to give you any points for your answer was wrong, as he demonstrated using Gauss’ law. You should, in science, believe logic and arguments, carefully drawn, not authorities…I’m not sure how I did it, but I goofed. And you goofed too, for believing me.

We both had bad luck.

Even the respected authorities can be wrong or misled by bias; in some cases (Fred Hoyle?) dramatically and chronically wrong. And the only way you can tell is by questioning assumptions and challenging claims and theories…even long-established ones. That is, perhaps, the most fundamental lesson you can teach your children about education in general, and science in particular.

Stranger

30

Feynman also said that “science is the belief in the ignorance of experts.” And along those lines, I like what (I believe) was something from a Wilson Mizner character, which I had posted on the wall in my classroom for many years: “I respect faith, but doubt will get you an education.”

31

OK, but even if you are talking about hydroxide instead of elemental oxygen, it’s still not combining with the sodium. All of the sodium ions and hydroxide ions are dissociated.