Microscopes and Magnification
Investigation One introduces students to the structures and functions of the human eye. Students explore sight and the resolution of detail through experiments and discussion. The hand lens is introduced as an aid to the naked eye. The hand lens is used by students to observe parts of the human eye not clearly resolved without the aid of magnification.
In Investigation Two, students investigate the properties of convex and concave lenses by viewing several objects. Students will investigate how each of the two lenses refracts light to either magnify or reduce the size of an object’s image. Using lenses, students will compare the abilities of the naked eye and the assisted eye to resolve the detail of an object.
Investigation Three introduces the ability of the compound microscope to magnify microscopic specimens. After learning the microscope’s parts, students practice the proper use and operation of the microscope by viewing two different slides.
Investigation Four gives students the opportunity to explore magnification by constructing a model lens from a drop of water. Students then use the three objectives of the compound microscope to view a slide. Students make observations of how much detail is visible and how the field of view is affected by the different powers of magnification of the three objectives. Students then calculate the total magnification of each of the three objectives and the hand lens.
In Investigation Five, students conduct further investigations to enhance their understanding of how a microscope functions. Students will construct a model of a microscope that incorporates a series of lenses to illustrate how the microscope refracts light and produces a magnified image.