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Activity: Kitchen Science - Spice It Up!

Examine Salt crystals, Sugar and various ground spices

Materials:

• Light microscope (with light source or mirror)
• Clean slide
• Several index cards or paper
• Tweezers (helpful but not required)
• Table Salt
• Sugar
• Black Pepper
• Other spices as desired

Procedure:

Clean your slides if necessary for the best images.

For each sample, first sprinkle a small amount onto index card or paper and transfer to the slide with tweezers (or sprinkle carefully).   Never return any experiment materials to their original containers !

Under low power, examine the salt crystals.

Examine the sugar, noting any differences from the salt crystals.

Examine the black pepper, again noting any differences from the salt.

Repeat for other spices if desired.

Questions:

What does the table salt look like? The salt is crystalline, that is, it takes on a natural structure similar to raw gemstones and natural minerals such as quartz.

What does the sugar look like?

What does the black pepper look like?

Many kitchen spices such as pepper and cinammon originate from plants and are produced by a grinding process. This results in randomly shaped pieces as opposed to the fairly uniform crystalline structure of salt.

Variations:

Examine the salt crystals while adjusting the microscope light source or mirror. They can also be examined using reflected light (see the experiment for solid objects). Dramatic changes in the contrast of the salt image can be obtained by experimenting with the light source and direction if possible. If your microscope has a mirror instead of a light source, greater changes in the image contrast and sharpness can be obtained.

Author:

Home Science Experimenters from Penacook, NH (11/99)

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