Heat-Sensitive Paper

September 11, 2009

Ron Perkins, Educational Innovationsby: Ron Perkins

A short time ago I received the following inquiry regarding our Heat-Sensitive Paper. One of the joys of being the president of Educational Innovations is having the opportunity to answer questions like this.

Q: What chemical coats your Heat-Sensitive Paper that makes it change color? My chemistry class wants to know the chemistry of what is happening on our heat-sensitive periodic tables. Can you pleaseHeat Sensitive Periodic Tables help us?

A: Some of the characteristics of our heat-sensitive periodic tables are easy to understand and some more challenging. The inks used provide color at lower temperatures and are colorless at higher temperatures. The change over temperature is called the “critical temperature.” Adding heat to the paper causes the paper to loose its color, an “endothermic” reaction. The reverse, going from colorless to colored, is an “exothermic” reaction and returns the heat.

To manufacture this paper, long rolls of white paper are unwound, coated on one side, dried, cut, and finally stacked into reams. Read the rest of this entry »

5 Comments | Chemistry, College level, Elementary level, High School level, Middle School level | Tagged: , , , , , | Permalink
Posted by Tami O'Connor

Back to School Experiments with Sodium Polyacrylate

September 8, 2009

Tami O'Connor, Educational Innovationsby: Tami O’Connor

Though I am no longer in a traditional classroom, the end of each August still fills me with that feeling of eager anticipation and yes, even a bit of anxiety…. Then I remember, I’m not going to be facing a room filled with bright new faces nor will I need to develop the plethora of creative lesson ideas necessary to engage and stimulate young minds. But still, I enjoy sharing some of the school experiments that my students and I enjoyed.

One school activity I used to teach the scientific method required the use of an old favorite; Sodium Polyacrylate. This is the chemical powder found in disposable baby diapers. I would start my lesson with a 3 Cup Monty game in which I used 3 opaque cups that were identical in every way except that two of the cups were empty and in the third I placed about 3 tablespoons of the water lock powder.

My shtick started with me talking about the importance of observation skills. I would explain the necessity of having a keen eye. Shortly after my speech I would pour about 1/2 of a cup of water into one of the empty cups. While encouraging my students to carefully watch the cup with the water in it, I would move the cups around fairly slowly, knowing they would be able to follow the water filled cup easily, until the three cups ended in a line across my desk. Read the rest of this entry »

1 Comment | Chemistry, Elementary level, experiments, High School level, Middle School level | Tagged: , , , , , , | Permalink
Posted by Tami O'Connor

The Amazing Ostrich Egg

August 27, 2009

by: Ken Byrne

The ostrich is a member of the Ratite family, which also includes emu, rhea, cassowary, and kiwi. Ratites are distinguished as flightless and keel-less (having no breast bone) birds. Ostrich skeletons and fossils date back over 120 million years.

The ostrich, native to Africa, is the largest of living birds. Some males reach a height of 8 ft (244 cm) and weigh from 200 to 300 lb (90 – 135 kg), while females will range between 5.5 and 6.5 (170 cm – 200 cm) feet tall at maturity.

In the wild, a mature female will lay between 12 and 15 eggs after mating (at the rate of one every other day for several weeks). Ostrich farmers quickly remove the eggs from the nest to extend the laying season. In some cases, a domesticated hen can lay up to 80 eggs, although 40 to 50 is more typical. Ostrich eggs are the largest of all bird eggs and weigh about 2.75 pounds (1.2 kg). The contents of one ostrich egg can be equivalent to as much as two dozen chicken eggs. Read the rest of this entry »

2 Comments | Biology, Elementary level, Middle School level | Tagged: , | Permalink
Posted by Tami O'Connor

Insects in Amber

August 24, 2009

Tami O'Connor, Educational Innovationsby: Tami O’Connor

What is Amber?

Millions of years ago large forests in some parts of the world began to seep globs of sticky, aromatic resin down the sides of the trees. Unlike sap, resin is produced to protect the tree from disease and injury and is extruded through the bark of the tree during rapid periods of growth.

As it continued to ooze, this resin would trap such things as insects, seeds, leaves and other light debris. As geologic time progressed, these forests were buried under sediment and the resin hardened and formed the soft, warm, golden gem we know today as amber. Most of the amber in the world ranges from 30 to 90 million years old and is found in sedimentary clay, shale and sandstones associated with layers of lignite. Read the rest of this entry »

4 Comments | Earth Science, Elementary level, Middle School level | Tagged: , , , , | Permalink
Posted by Tami O'Connor

Shark Teeth

August 19, 2009

Laurie Neilsenby Laurie Neilsen

In honor of The Discovery Channel’s Shark Week, here are some common questions asked about shark teeth, and some meaty facts to sink your teeth into.

Q. Why are some shark teeth black and others are tan?

A. The color of a fossil shark tooth is dependent upon the sediment in which it settled. As minerals slowly replace the calcium in the tooth, it changes to the color of the minerals. Color does not necessarily indicate age in a shark tooth fossil. It usually indicates the region from which the tooth was collected. Our fossilized shark teeth are collected from Morocco.

Fossilized Shark Teeth

Read the rest of this entry »

1 Comment | Biology, Elementary level, High School level, Middle School level | Tagged: , , , , , | Permalink
Posted by Tami O'Connor

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