A microscope is a device used for observing objects that
are too ___1___ to
be seen by the naked or unaided eye. the science of
investigating small objects using such an instrument is
known as microscopy. The purpose of microscopes has
been to give us a better ___2___
of the world we live in by allowing us to take a closer
look. Microscopes offer us a closer look in two ways --
they magnify and they resolve an image of a specimen. A
specimen is the term given to any object that scientists
study under a microscope. Magnification is the
enlargement of an image while resolution is the ability
to produce an image that is clear enough to distinguish
closely spaced ___3___
of the specimen.
Microscopes can largely be separated into two classes
-- optical microscopes and scanning probe microscopes.
Optical microscopes are microscopes which function ___4___
the optical theory of lenses in order to amplify the
image created by the channeling of a wave through the
sample. The waves used are either electromagnetic in
optical microscopes or electron beams in electron
microscopes. Electron microscopes, which use beams of
electrons instead of light, are intended for very high
magnification sage. In scanning probe microscopy, a
physical probe is used in close proximity to the sample
or nearly touching it. A probe scans across the sample,
and by measuring the interactions between the sharp tip
of the probe and the sample, a micrograph is ___5___. |