An electron microscope is a scientific instrument which uses a beam of electrons to
examine objects on a very fine scale. In an optical microscope, the wavelength of light
limits the maximum magnification that is possible. As electrons have a smaller
wavelength, they can achieve a higher magnification, and can see very small objects –
typically around 1,000 times smaller than those seen in an optical microscope. The
outline of objects, as revealed by the flow of electrons, is changed into a picture using
visible light for people to see.
FM broadcasting is a method of radio broadcasting using frequency modulation (FM)
technology. Invented in 1933 by American engineer Edwin Armstrong, it is used
worldwide to provide high-fidelity sound over broadcast radio.
FM broadcasting is capable of better sound quality than AM broadcasting, the chief
competing radio broadcasting technology, so it is used for most music broadcasts. FM
radio stations use the VHF frequencies. The term “FM band” describes the frequency
band in a given country which is dedicated to FM broadcasting.
Nuclear fission is a process used to create energy. It is when an atom splits apart into
smaller atoms. The process gives off a lot of energy, and is used in nuclear weapons and
nuclear reactors. Nuclear fission was discovered in December 1938 by the German
nuclear chemist Otto Hahn and his assistant Fritz Strassmann in Berlin.
A transistor is an electronic component that can be used as an amplifier, or as a switch.
It is made of a semiconductor material. They behave like vacuum tube triodes, but are
much smaller, more reliable, and use much less power. Transistors are found in most
electronic devices.
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