November 12, 2010
by: Michelle Bertke and Melanie Bunda
Bubbles are always a fun and interesting activity for kids of all ages. However, bubbles are not only fun, they are also an excellent teaching tool for some abstract concepts such as air density, dissolved gasses, and air pressure. Below is a collection of bubbly activities that highlight each of these topics. Educational Innovations offers a full line of wonderful bubble products!
Gravity Defying Bubbles
Different gasses have different densities. The air around us is mostly nitrogen (N2) and oxygen (O2), which are both lighter than carbon dioxide (CO2). When a heavy gas, such as CO2 is placed in a tank, it will sink to the bottom without mixing. This can be achieved by placing a few blocks of dry ice in a large fish tank or clear plastic bin covered loosely with a lid and allowing them to sublime. This will take several minutes. Always use caution when handling dry ice by using proper gloves and safety goggles. Once full, blow bubbles over the surface of the tank. When the bubbles reach the interface of the two gasses, they will float. If you fill the tank with CO2 unnoticed, have the kids speculate as to why they think the bubbles didn’t reach the bottom, and what might be in the tank. An alternative is to fill a balloon with CO2 by filling it with baking soda (or an alka seltzer tablet) and placing it over the opening of a bottle filled with vinegar (or water). Lift the balloon so the contents spill into the bottle and react with the liquid, allow the balloon to fill from the reaction, twist and remove. Use it to blow bubbles. Compare these bubbles to those blown with regular air (use a fan, not your breath for best results). Have students compare the two bubbles. Which one falls faster? Which one floats longer? Read the rest of this entry »
November 3, 2010
by: Elaine Kotler
I created a lab using the Instant Snow Polymer (Sodium Polyacrylate) from Educational Innovations that I use in my 8th grade Physical Science Class as well as Summer School Programs that I teach for grades 4-9. This lesson incorporates concepts of Conservation of Mass, Properties of Matter, Metric Measurement and Conversion, and Observation Skills. The lab, as I give it to the students, is listed below.
Each student receives an empty baggie to be used for comparison, a baggie containing 12 grams of Instant Snow Polymer, use of a balance and a graduated cylinder.
I have already explained the Law of Conservation of Mass, and Density (they need to remember that the density of water is 1 g/ml, or look it up) prior to introducing this lab activity. However, they do not know the terms exothermic, endothermic, hydrophobic or hydrophilic. My students are allowed to look them up, but unless they make careful observations as they are conducting the experiment, they won’t be able to answer the questions later.
The final question “What is That Stuff?” garners some interesting answers. Some recognize a use for it as snow for ski slopes; others have suggested material for ice packs. One suggestion was to use the powder to help clean up and absorb spills. Read the rest of this entry »
November 1, 2010
by: Gordon R. Gore
BIG Little Science Centre
Educational Innovations has a new product called Gigantic Growing Spheres (Catalogue #GB-760) which physics teachers might find useful for illustrating internal reflection. These are a very large version (about 6 cm) of the Growing Spheres (also called Jelly Balls) discussed in earlier issues of BIGScience*.
Basic Equipment Needed
1 green* laser pointer (* works much better than red)
1 fully grown ‘Giant Growing Sphere’ (about 6 cm diameter)
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