| | | | | same. |
| This article teaches kids about chemistry and is an | | | | Although these chemicals are not harmful to your |
| excellent introduction to the totally fun activities in | | | | skin, they can cause your skin to dry out and itch. |
| homeschool chemistry (including exothermic | | | | Wear gloves (latex or similar) and eye protection |
| reactions, phase shifts, and acid indicators). | | | | (safety goggles), and if you're not sure about an |
| It’s also good for boy scouts working on a | | | | experiment or chemical, just don't do it. (Skip the |
| badge, or for any kids that love science | | | | peroxide and cold pack if you have small kids.) |
| experiments. These experiments are part of a | | | | What about the red cabbage? Red cabbage juice |
| homeschool science program that I teach, and I | | | | has anthocyanin, which makes it an excellent |
| promise your kids will love it. | | | | indicator for these experiments. Anthocyanin is |
| Chemistry is an exciting subject for kids of any | | | | what gives leaves, stems, fruits, and flowers their |
| age, especially if you set up a natural discovery | | | | colors. Did you know that certain flowers like |
| environment for them to safely explore in. Let's | | | | hydrangeas turn blue in acidic soil and turn pink |
| find out how to do this with your own | | | | when transplanted to a basic soil? This next step |
| homeschool science learning environment. | | | | of the experiment will help you understand why. |
| At a university, one of the first things you will | | | | You'll need to get the anthocyanin out of the |
| learn about in your chemistry class is the | | | | cabbage and into a more useful form, as a liquid |
| difference between physical and chemical changes. | | | | "indicator". |
| An example of a physical change happens when | | | | Prepare the indicator by coarsely chopping the |
| you change the shape of an object, like wadding | | | | head of red cabbage and boiling the pieces for |
| up a piece of paper. If you light the paper wad on | | | | five minutes on the stove in a pot full of water. |
| fire, you now have a chemical change. You are | | | | Carefully strain out all the pieces (use a fine mesh |
| rearranging the atoms that used to be the | | | | strainer) and the reserved liquid is your indicator |
| molecules that made up the paper into other | | | | (it should be purple). |
| molecules, such as carbon monoxide, carbon | | | | When you add this indicator to different |
| dioxide, ash, and so forth. | | | | substances, you will see a color range: hot pink, |
| How can you tell the difference between physical | | | | tangerine orange, sunshine yellow, emerald green, |
| and chemical changes? There's an easy way to | | | | ocean blue, velvet purple, and everything in |
| tell if you have a chemical change: if something | | | | between. Test out the indicator by adding drops |
| changes color, gives off light (like the light sticks | | | | of cabbage juice to something acidic, such as |
| used around Halloween), heat is absorbed (gets | | | | lemon juice and see how different the color is |
| cold) or produces heat (gets warm). Some quick | | | | when you add indicator to a base, like baking soda |
| examples of physical changes include tearing cloth, | | | | mixed with water. |
| rolling dough, stretching rubber bands, eating a | | | | Have your indicator in a bottle by itself. Old soy |
| banana, or blowing bubbles. | | | | sauce bottles or other bottles with a built-in |
| Shopping List: | | | | regulator that keeps the pouring to a drip is |
| § Rubbing alcohol (largest bottle) | | | | perfect. You can also use a bowl with a bulb |
| § Hydrogen peroxide (largest bottle) | | | | syringe, but cross-contamination is a problem. Or |
| § Baking soda (largest box you can find) | | | | not – depending if you want kids to see the |
| § Distilled white vinegar (largest size) | | | | effects of cross-contamination during their |
| § Washing soda (near the laundry soap) | | | | experiments. (The indicator bowl will continually |
| § Citric acid (optional, but nice to have) | | | | turn different colors throughout the experiment.) |
| § One head of red cabbage | | | | Your mission: To find the reactions that generate |
| § Clear ivory dish soap (small bottle) | | | | the most heat (exothermic), absorb the most |
| § Alum (check the spice section) | | | | heat (endothermic), and which are the most |
| § Single-use cold pack (not the gel kind) | | | | impressive in their reaction (the ohhhh-ahhhhh |
| § Plastic zipper bags and old water bottles | | | | factor). |
| § Muffin cup baking tray (12 cups or more) | | | | The Experiment: Start mixing it up! When I |
| | | | personally teach this class, let them have at all the |
| Let's mix up chemicals that bubble, ooze, freeze, | | | | chemicals at once (even the indicator), and of |
| and change colors. Before we start, you'll need to | | | | course, this leads to a chaotic mix of everything. |
| get these items together: a muffin cup baking | | | | When the chaos settles down, and they start |
| tray, water, vinegar (acetic acid), baking soda | | | | asking good questions, I reveal a second batch of |
| (sodium bicarbonate), washing soda (sodium | | | | chemicals they can use. (I have two identical sets |
| carbonate), rubbing alcohol, hydrogen peroxide, | | | | of chemicals, knowing that the first set will get |
| citric acid, ammonium chloride (don't activate the | | | | used up very quickly.) |
| cold pack, but instead cut open and empty the | | | | Tip for Testing Chemical Reactions: Periodically |
| contents into a plastic bag and discard the water | | | | hold your hand under the muffin cups to test the |
| pouch inside), aluminum sulfate ("alum" in the spice | | | | temperature. |
| section of the grocery store or drug store), a | | | | |
| head of red cabbage and a clear liquid dish soap | | | | After the initial burst of enthusiasm, your |
| such as Ivory. | | | | homschool science students will intrinsically start |
| Cover your kitchen table with a plastic tablecloth | | | | asking better questions. They will want to know |
| (if you have small kids, put another tablecloth on | | | | why their green goo is creeping onto the floor |
| the floor to catch the spills). Place your chemicals | | | | while someone else just bubbled up hot pink, |
| on the table. A set of muffin cups make for an | | | | seemingly mixed from the same stuff. Give them |
| excellent chemistry experiment lab. (Alternatively, | | | | the change to figure out a more systematic |
| you can use empty plastic ice cube trays.) You | | | | approach, and ask if they need help before you |
| will mix in these cups. Leave enough space in the | | | | jump in to assist. |
| cups for your chemicals to mix and bubble up | | | | Homeschool Science Teaching Tips: You can make |
| – don't fill them all the way when you do your | | | | this lab more advanced by adding a postage scale |
| experiments! | | | | (to measure the solids in exact measurements), |
| Set out your liquid chemicals in easy-to-pour | | | | small beakers and pipettes for the liquid |
| containers, such as water bottles (be sure to label | | | | measurements, and data sheets to record |
| them, as they all will look the same): alcohol, | | | | temperature, reactivity, and acid/base indicator |
| hydrogen peroxide, water, acetic acid, and dish | | | | levels. Hint – make the data sheet like a |
| soap (mixed with water). Set out small bowls (or | | | | matrix, to be sure you get all the possible |
| zipper bags if you're doing this with a crowd) of | | | | combinations. |
| the powders with "scoopers" made of the tops | | | | Use the indicator both before and after you mix |
| of your water bottles. The small "scoopers" | | | | up chemicals, and you will be surprised and dazzled |
| regulate the amounts you need for a muffin-sized | | | | by the results! |
| reaction. Label the powders, as they all look the | | | | |