| |
Physics for kids ages 7 to 9
Smooth
Purpose To model cleavage of a mineral.
Materials sheet of newspaper
Procedure
1. Hold the sheet of newspaper with both hands so that your thumbs meet in the
center along the top of the sheet.
2. Tear the sheet of paper in half from top to bottom.
Results The paper tears in a relatively
straight line down the page.
Why? One of the ways a mineral breaks is by
cleavage. Cleavage is the property of a mineral that allows it to break along a
flat smooth area called a cleavage plane. Along the cleavage plane, the bonds
between atoms are relatively weak. (Bonds are forces that link atoms, groups of
atoms, or molecules together.) The fibers making up a sheet of newspaper are
generally lined up from the paper's top to bottom. Tearing the paper from top
to bottom breaks the lined-up fibers apart in a relatively straight, smooth
line, much like breaking a mineral along a cleavage plane breaks the mineral
apart, exposing two smooth edges.
|
