The Microscope th Grade Science

Microscope A microscope is an instrument for viewing objects that are too small to be seen easily by the naked eye. A microscope is an instrument for viewing objects that are too small to be seen easily by the naked eye. Micro - means very small. Micro - means very small. Scope - is a device to look at something. Scope - is a device to look at something. Uses more than one lens - the image magnified by one lens can be further magnified by another. Uses more than one lens - the image magnified by one lens can be further magnified by another. Molecular Expressions Photo Gallery Molecular Expressions Photo Gallery

How to Make a Simple Microscope Get 2 magnifying glasses and a sheet of printed paper. Get 2 magnifying glasses and a sheet of printed paper. Hold one magnifying glass a short distance above the paper. The image will look a bit larger. Hold one magnifying glass a short distance above the paper. The image will look a bit larger. Place the second magnifying glass between your eye and the first magnifying glass. Place the second magnifying glass between your eye and the first magnifying glass. Move the second glass up or down until the print comes into sharp focus. Move the second glass up or down until the print comes into sharp focus.

Examples of Magnification Examples of Magnification Types of Microscopes Compound Microscope Compound Microscope –Containing two or more lenses –Uses light to magnify –High magnification/Low resolution –Most commonly used microscope –$150 - $1,500 Transmission Electron Microscope (TEM) Transmission Electron Microscope (TEM) –Used to study parts inside cells –Uses electron beams used to magnify –High magnification/High resolution –$50,000

Microscope Lenses Lens Lens –Piece of clear material that has been shaped to cause light rays to pass through it to meet or spread out Concave Lens Concave Lens –A lens that is curved inward Convex Lens Convex Lens –A lens that is curved outward

Microscope Terms Magnify Magnify –To make an object look bigger Reflect Reflect –To throw back light rays that strike a surface Refraction Refraction –The bending of light rays as they pass through one substance to another

1. Eyepiece Where you look into the microscope. Where you look into the microscope.

2. Body Tube Light passes from the objective lens to the eyepiece. Light passes from the objective lens to the eyepiece.

3. Rotating Nosepiece The objective lenses are mounted in this part. The objective lenses are mounted in this part.

4. Objective Lenses 2 or 3 mounted on the nose piece. Each one magnifies a different power. 2 or 3 mounted on the nose piece. Each one magnifies a different power.

5. Arm This part supports the entire upper portion of the microscope. This part supports the entire upper portion of the microscope.

6. Coarse Adjustment Knob Focus This part allows you to move the upper portion of the microscope. This part allows you to move the upper portion of the microscope.

7. Fine Adjustment Knob Focus Once the object that you would like to view comes into focus; you use this to fine tune the image. Once the object that you would like to view comes into focus; you use this to fine tune the image.

8. Slide A thin piece of glass where you place a specimen.

9. Stage The flat place under the objective lens where you place a slide for viewing. The flat place under the objective lens where you place a slide for viewing.

10. Stage Clips These two things keep the slide from moving around on the stage. These two things keep the slide from moving around on the stage.

11. Aperture The opening in the stage that allows light through. The opening in the stage that allows light through.

12. Diaphragm This disk under the stage controls the amount of light that passes through the aperture. This disk under the stage controls the amount of light that passes through the aperture.

13. Mirror or Light Source This provides light so that it is easier to see the object that you are viewing. This provides light so that it is easier to see the object that you are viewing.

14. Base Supports the microscope and is used to carry it. Supports the microscope and is used to carry it. Bottom part of the microscope. Bottom part of the microscope.

15. Legs The mirror or lamp is located between these. The mirror or lamp is located between these. Bottom part of the microscope. Bottom part of the microscope.

Using the Microscope When carrying a microscope, grasp the arm with one hand and put your other hand under the base. You will NOT move the microscopes in the lab. When carrying a microscope, grasp the arm with one hand and put your other hand under the base. You will NOT move the microscopes in the lab. Start by adjusting the nosepiece to the lowest power objective tube (the shortest one) Start by adjusting the nosepiece to the lowest power objective tube (the shortest one) Make sure your slide is on the stage. Make sure your slide is on the stage. Looking through the eyepiece, slowly adjust the coarse adjustment knob until the specimen comes into focus Looking through the eyepiece, slowly adjust the coarse adjustment knob until the specimen comes into focus Make sure the lens does not hit the slide Make sure the lens does not hit the slide Slowly adjust the fine adjustment knob until the specimen comes into focus Slowly adjust the fine adjustment knob until the specimen comes into focus

What’s my power? To calculate the power of magnification, multiply the power of the eyepiece ocular lens by the power of the objective lens. 10 x 40 = 400 The eyepiece lens usually has a power of 10 x

What happens as the power of magnification increases? We can see better details with higher the powers of magnification, but we cannot see as much of the image.