The use of dynamic audio-visual aids in the classroom has become widely accepted.  Personal computers connected to small video projectors are now commonly used in Middle School science classrooms to present videos and oral presentations.  Brief descriptions of some of the presentations that RESEED volunteers and their teacher partners use appear on this page.  These A-V presentations are available to volunteers and web site guests in Microsoft PowerPoint® file format. Send an e-mail to drjcast@aol.com using the keyword(s) shown below for the specific presentation(s) you would like to view in the subject line of the e-mail. Please include your name, affiliation and the reason for your interest in the topic.

The Structure of Simple Carbohydrates

This lesson describes the nature carbohydrates and teaches students the difference between molecular formulas and structural formulas. Keyword: Carbohydrates

Glue Ball Chemistry

The nature and structure of polymers are discussed in this presentation. In addition, the students are instructed to perform a simple experiment that enables them to convert a small amount of Elmer’s glue to a rubber ball using the concept of polymer “cross-linking.”   Keywords: Glue Ball
 
Physical and Chemical Changes

The differences between physical and chemical changes as well as the clues to a chemical reaction are described in this presentation.  It is used as a prelude to the demonstration of “Halloween Colors,” the reaction between hydrogen peroxide and potassium dichromate, which involves multiple chemical reactions occurring at different rates.  Keywords: Halloween Colors

Laws of Conservation of Mass and Definite Proportions

The two laws are defined and the reaction between sodium bicarbonate and acetic acid is analyzed in detail.  The presentation is used prior to a demonstration with a rigid bottle containing the reactants on a triple beam balance. The calculations are shown to prove that the mass of the products of a chemical reaction are equal to the mass of the reactants, and that the law of definite proportions is followed.  Keyword: Mass Conservation Lesson

The Difference between Mass and Weight

This short lesson explains the difference between mass and weight and their connection. Keyword: Mass-Weight

The Measurement of pH

The definition of pH, how the scale is made, and the techniques used to measure it are described.   This presentation is intended to be used in conjunction with the activity where students prepare  dilute solutions of orange juice and measure their pH.  Keywords: Measuring pH

Origin of the Elements

Theories of how the universe was formed and the origin of the elements are described. Starting with hydrogen, the lesson shows how the elements were created by nuclear fusion in stars, novas, and supernovas.   Keyword: Origin

Oscillating Chemical Reaction

This presentation includes a video that shows the Briggs-Rauscher reaction, a rare example of an oscillating chemical reaction that produces alternating changes in color over many cycles.  The discoverers of the reaction are high school teachers, so the chemistry described in the presentation is aimed at advanced Middle School students.  Keywords: Oscillating Reaction

Self Darkening Sunglasses

An example of a reversible chemical reaction used in glasses that darken in sunlight and become clear in ordinary room is briefly described.  The concept is known as “photochromism” and the presentation shows how the molecule’s structure changes from one form to another in light and dark.  Keywords: Photochromic Glasses

The Scientific Method

Intended for presentation early in the first semester of Middle School physical science, this talk covers the definition of science, discusses how scientists work, and outlines the steps involved in the scientific method. There is also a discussion of measurements and the importance of science in today's world. Keywords: Scientific Method

Another presentation uses the example of the discovery and development of liquid crystal displays to show how the scientific method was applied.  Keywords: Science Methods at Work

The Dehydration of Sucrose

This short presentation is given prior to the demonstration of the acid-catalyzed decomposition of common table sugar (sucrose).  The mechanism of the dehydration reaction that occurs is shown by the use of structural formulas. Keywords:  Sucrose Dehydration

The Meaning and Use of Pi

A short presentation of how the constant pi was derived and how it is used. Keywords: Meaning of Pi 

Liquid Crystals: A Unique State of Matter

Although not part of the required curriculum, this PowerPoint presentation is given to teach students about liquid crystals and how they are used in today's ubiquitous flat panel displays for computers and television as well as cell phones and other hand-held devices.  Keywords:  LCD Lesson

Rocket Science Fundamentals

Some middle schools have elective courses in aeronautics and rocket science/engineering.  This eight minute slide show is an introduction to rocketry and includes some work that was done at Thiokol Chemical Company in the 1960s.  The structure of the Minuteman III Intercontinental Ballistic Missile as well as some future propulsion system designs are also presented. Keywords: Rocket Science