MICROSCOPES

Some objects are so small that our eyes cannot see them. We cannot see atoms or molecules, or the cells of our bodies, or viruses that carry disease. A microscope uses lenses to make tiny things appear bigger so we can see them clearly. There are two main kinds of microscope. Optical microscopes create a magnified image using light from an object. Electron microscopes are much more powerful and use a beam of electrons instead of light.

OPTICAL MICROSCOPE

An optical microscope uses light. The object to be viewed is cut very thin so light will pass through it, then placed on a piece of glass called a slide. A mirror at the bottom gathers light and reflects it up through the slide. A system of lenses magnifies the object, making a bigger image that may be seen in the eyepiece at the top.

ELECTRON MICROSCOPE

An electron microscope uses a beam of electrons instead of light. The object to be viewed is placed on a small stand in the middle. An electron gun, similar to the ones in TV sets, fires a beam of electrons down onto the object. As the electron beam scans (passes over) the object, a very detailed picture of the object appears on a TV screen.

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