Can an optical microscope be used to observe molecular structures?
The molecular structure can be observed with an electron microscope, which now has a magnification of 15 million times.
In the 1970s, the transmission electron microscope was one of the more popular microscopes at present. Its resolution was about 0.3 nanometers, and the human resolution ability was about 0.1 millimeters. That was the initial state of the development of electron microscopes.
In 1931, a German scientist modified a high-voltage oscilloscope using a cold cathode discharge electron source and a three-electron lens. After the modification, he found that the oscilloscope could magnify objects several times. In this way, he invented the transmission electron microscope, and the invention of the high-voltage oscilloscope also confirmed the magnification function of the electron microscope to the world.
At the beginning of the 20th century, American scientists made new breakthroughs in the research on the resolution of electron microscopes, and soon reached the modern level. At this time, electron microscopes also developed rapidly in China.
Now the magnification of electron microscopes can reach 15 million times, while the magnification of optical microscopes is only 2000 times. This is also the difference between electron microscopes and optical microscopes, so we can directly observe atoms in metals through electron microscopes. conditions and the orderly arrangement of atoms in semiconductors.
The resolving power of electron microscopes is still far superior to that of optical microscopes. The maximum magnification of an optical microscope is about 2,000 times, while the maximum magnification of a modern electron microscope is more than 3 million times. Therefore, the atoms of certain heavy metals and the neatly arranged atomic lattice in the crystal can be directly observed through the electron microscope (note that only You can't see the atomic structure clearly when you see the arrangement, and you can't see it with a molecular-level electron microscope. What you can see under the microscope is the crystalline shape of molecules with different configurations)
Current microscopes are basically unable to see molecules, not because the magnification is not enough, but because the resolution of optical microscopes cannot be reached. The current high-resolution STORM is about 20nm, which means that two points separated by more than 20nm can be seen clearly, and the image below 20nm is a lump.
Molecules are basically at least at the nanometer level. If you use an electron microscope, it is hard to tell. The magnification of the electron microscope can already reach 10,000 times, and the resolution of the electron microscope is nanometer level. At the same time, I want to tell you that the resolution is very important. , if the resolution cannot be achieved, high magnification is useless.
