Elements, Compounds, and Mixtures

Marcea Anderson                    Thornton Township High School
                                   150th & Broadway Ave.
                                   Harvey, Ill. 60426
                                   708-596-1000

Objectives:

To distinguish and describe the three types of matter: elements, compounds, 
mixtures. 

Apparatus:
 
Helium balloon, beaker of salt, taco salad appetizer, petri dishes, nuts, bolts, 
washers, overhead projector.

Strategy:

     Before class begins, set out a beaker of salt, tie a helium balloon to the 
desk and bring out a taco salad with chips.  When the students get to class have 
them wash their hands.  Ask the students why you would have these three items 
out on the desk and ask them to come up and sample the taco salad.  

     Instruct the students to form their mini-groups and discuss the three 
items.  Each group should make a list comparing and contrasting their three 
items.  Discuss their lists.  Hopefully, one group will determine that the 
helium balloon is an element, the salt is a compound, and the taco salad is a 
mixture.  Define the three types of matter on the board or overhead.  

     To show the difference between each type of matter use nuts, bolts and 
washers in plastic petri dishes.  Set these up in advance for use with an 
overhead projector.  

    For elements use the following:
Dish A 8 washers 
     B 8 bolts
     C 8 Nuts

    For compounds use the following:
Dish D combine 1 nut with 1 bolt making several sets
     E combine 2 nuts with 1 bolt making several sets
     F combine 1 bolt, 2 washers and 2 nuts making several sets

    For mixtures use the following :
Dish G 2 washers, 2 bolts, 2 compound D and 1 compound F
     H 5 washers, 6 nuts and 4 bolts
     I 4 compound D, 3 compound E and 5 compound F

    Show each dish and explain why it is like its type of matter.  Use these to 
review the concept of each type of matter.  Have the students form their groups 
again.  This time, ask them to make an analogy of the concept of elements,  
compounds, and mixtures from their daily life.