Substances and Properties

Mark Wagner                    Mark Sheridan
                               533 W. 27th Street
                               Chicago, IL 60616

Objective(s):

Students will observe and list properties of various substances.

Materials Needed:

Elmer's or other "white"  glue 
Saturated Borax solution
Cups
Stirring sticks

Strategy:

Discuss the meaning of the word "properties" with the students (see below).  Give students 
access to the materials.  Give students the instructions for making "Poly-Glue."  
Tell students to make a list of the properties of the ingredients for the poly-
glue and a list of the properties of the "poly-glue."  You may also ask the 
students to answer the following questions.
     1. What properties of the new substance are the same as the properties of 
        its ingredient?
     2. What properties of the new substance are different from the ingredients?
     3. Can you think of any explanation for these new properties?
    
After students have completed the activity hold a classroom discussion of their 
results. 

Properties--When we use our senses to observe a substance, we are discovering 
some of its properties. Color, smell, texture, shape, size and feel are some of 
the properties of a substance that we can easily determine by using our senses.  
Some properties are discovered by observing the behavior of a substance when we 
do things to ir.  Does it bounce when dropped?  Does ir pour easily or is it 
"sluggish/"  Does it break easily when hit?

There are other properties that we could also discover by using lab equipment to 
conduct tests:
     1. Can electricity pass through the substance easily?
     2. Is the substance attracted by a magnet?
     3. Does the substance produce bubbles when vinegar is placed on it?

The answers to these questions would require the use of equipment as well as 
our senses to discover but would also be considered properties of a substance.  
In today's activity, we will not be conducting tests using special equipment.  
Sorry!


Today's Activity
 In this activity you will mix different ingredients to make new substances.  
Using your senses (except taste) you will:
     1. Observe the ingredients and make a chart of their properties.
     2. Observe the new substances and chart their properties.
     3. Compare the properties of the new substances to the properties of the 
ingredients. How are these properties the same and different?

Make a chart for your lists of properties.

Directions for Making Poly-Glue
Materials: white glue, Borax solution, cups, stirring stick

Get equal volumes of glue and Borax solution each in its own cup.  Pour a small 
amount of Borax solution into the glue using a stirring stick to mix them 
together.  As the mixture gets stiffer, knead with your hands adding borax as 
needed.  The finished polymer should form a rubbery ball.

Performance Assessment:

Give students a different set of ingredients to be combined to make a new 
substance.  An example might be giving them salt, flower, and colored water.  
when mixed these produce "play clay."

Students should be able to list several properties of the ingredients and of the 
"play clay" using more than one sense.

References:
A Demo a Day (A Year of Chemical Demonstrations) by  Borislaw Bilash II, George R. 
Gross, and John K. Koob; published by Flinn Scientific, INC.  (708) 879-6900