Understanding Magnification and Scale
(student activity sheet)
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science
Name: Class: Date:
Salt Crystals
Introduction:
Understanding magnification and scale is vital to the use of a microscope
and the analysis of what is observed. In this activity, you will explore
magnification and scale using the digital capabilities of the digital microscope
and by building models. You will refer back to this activity and build upon it in
subsequent activities.
Procedure:
1. Examine crystals of table salt using your naked eye. (Try pouring a small amount of salt onto a dark piece of paper.)
• Describe a salt crystal.
• Draw a picture of a salt crystal.
• Measure the size of a salt crystal, in millimeters, as best you can and record this information.
2. Place a number of salt crystals on a microscope slide.
3. Working with a partner, examine the salt at 40X magnification (i.e., the 4X lens) using the eyepieces on the microscope.
Do NOT use the mini-digital screen or computer screen.
• Describe a salt crystal as viewed under the microscope at 40X. Focus on what details you can see at this magnification
that you could not see before.
• Draw a picture of a salt crystal as viewed at this magnification.
• Draw a picture of the entire field of view of the microscope at this magnification. The field of view is the entire circle,
or area, that can be seen.)
• Measure the size of a salt crystal, in microns, using a transparent ruler, and record this information.
• A micron, or micrometer (symbol μm), is one millionth of a meter or one thousandth of a millimeter:
1000 microns = 1 millimeter.
• Measure the diameter of the field of view, in millimeters or microns, and record this information.
4. Make a physical model of a 40X magnification salt crystal.
• Calculate the dimensions of a model crystal that is 40X the size of an actual crystal.
• Use clay and a ruler to make a 3-dimensional model of the appropriate size.
5. Repeat the observations and model-making for 100X (i.e., the 10X lens) and 400X (i.e., the 40X lens).
• Notice and record additional details about the crystals as the magnification increases
6. Repeat the observations for 1000X (i.e., the 100X, oil immersion lens).
• Why are you not asked to make a physical model of a 1000X magnification salt crystal?
Safety
Remember to practice proper safety techniques
in all science laboratory activities!
!
