Cycle II Materials Science

John Dewey High School

Mr. Klimetz

Symmetry in Common Objects

Interactive Exercise

As we have seen from our laboratory study and modeling of crystals and crystal shapes, the regular and predictable spatial arrangement of (external) crystal faces is a direct reflection and outgrowth of the orderly and patterned internal arrangement of its atoms and molecules. Careful study of crystal shapes and their respective geometries provide valuable clues into the molecular infrastructure and architecture of the matter of which they are comprised. However, crystals and objects comprised of crystalline matter are not the only objects which seek or follow a symmetrical plan of arrangement. There is scarcely any object in our everyday world, both natural and synthetic (man-made), which does not possess some expression of symmetry.

The following is a list of common objects to which you all have access. Find examples of them either in your house, yard, street or general neighborhood and describe the symmetry elements present (if any). As you may recall, the three symmetry elements are the plane (mirror), the line (rotational axis) and the point (inversion). Study each object carefully and fully, observing it from all perspectives and views.  On the line adjacent to the object, list the element(s) present and the reason why. Some objects may possess more than one symmetry element. List all that you have discovered and explain.

ObjectSymmetry Element(s) and Explanation

Refrigerator 

Kitchen Stove     

Yourself

Television Set     

Front Door to Your Home 

Automobile 

    

Starfish 

Barbells

Pencil   

Tree

Slice of Bread   

Coat Hanger

Blue Jeans 

Uncooked Egg 

Compact Disc    

Open Umbrella   

Airplane

Computer Monitor     

Fingernail    

Your Left Foot     

Textbook     

Backpack   

Eyeglasses

Bicycle  

Paper Towel Roll

Bathtub

The Dewey Monument     

Ceiling Fan

Subway Car

Name _________________________

Date __________________________