MICROSCOPES 4th Quarter 2008

MICROSCOPES MAGNIFIES OBJECTS (MAKES OBJECTS LOOK BIGGER) HELP SCIENTISTS STUDY OBJECTS & LIVING THINGS TOO SMALL TO SEE WITH THE NAKED EYE compound light microscopeWe use a compound light microscope

3 Types of Microscopes simple microscope has only 1 lens. compound microscope has 2 sets of lenses. It can magnify things times larger than they really are. electron microscope can magnify objects up to 300,000 times. They do not use lenses, but use electrons to enlarge the image.

PARTS OF A MICROSCOPE 1.eyepiece the lens of the microscope that you look through 2.course adjustment the large knob on the microscope that you turn to bring the object into COARSE focus 3.fine adjustment the small knob on the microscope that brings the image into SHARPEST focus

PARTS OF A MICROSCOPE 4.arm the part of the microscope supporting the body tube 5.body tube the part that holds the eyepiece and the objective lenses. 6.nosepiece the part at the bottom of the body tube that holds the objective lenses and allows them to be turned

7.-high power objective lens the lens that magnifies the object the greatest amount. (usually 40x) -Low power (scanner) objective lens the lens that magnifies the object the least amount (usually used to find the object; magnifies only 3 or 4 times) -middle power objective lens the lens that usually magnifies the object more than the scanner lens, but less than the high power lens (usually 10x to 20x)

8. stage the flat part below the objectives lens where the slide is placed 9. clip the part that holds the slide in place so it doesn’t move 10. diaphragm the part that controls the amount of light entering the field of view

11. light source the lamp (or mirror) under the stage that sends light through the object being viewed. 12. base the bottom part that supports the rest of the microscope

GOLDEN RULE Before doing ANYTHING with your microscope, be sure that: 1.) STAGE IS ALL THE WAY DOWN 2.) ON Low power

Making a Wet Mount Slide 1. Use dropper to place a drop of water on the center of a clean slide. 2. Use tweezers to lay specimen on the drop of water. 3. Gently touch the cover slip to the edge of the drop of water to cover the specimen & the water.

Appearance of the Specimen Objects appear upside-down & backward Movement appears to be in opposite direction than actual movement 1 2 move slide slide appears to move 2 1

Field of View Field of view is the area (circle) that you see when looking through the eyepiece

Calculating Magnification 1. Find the power of the lens. It is found on the side of the lens. Magnification power of a lens is always identified by the label of x (10x, 1000x) 2. Multiply the power of the eyepiece by the power of the objective lens. 3. Examples: eyepiece obj. lens 10x times 100x 10x times 50x 10x times 40x

Recording Observations Draw specimen large enough to fill “field of view” circle Draw as many details as possible Drawing should be neat Label specimen Label power of magnification Name & date on paper