Can molecular structure be observed with a light microscope?
The molecular structure can be observed using an electron microscope, which now has a magnification of up to 15 million times.
In the 1970s, transmission electron microscopy was a popular type of microscope with a resolution of about 0.3 nanometers, while human resolution was about 0.1 millimeters, which was the initial state of electron microscopy development.
In 1931, a German scientist modified a high-voltage oscilloscope by combining a cold cathode discharge electron source and a lens with three electrons. After modification, he found that the oscilloscope could magnify objects several times. Thus, he invented the transmission electron microscope, and the invention of the high-voltage oscilloscope confirmed the magnifying function of the electron microscope to the world.
At the beginning of the 20th century, American scientists made new breakthroughs in the study of the resolution of electron microscopes, which quickly reached modern levels. At this time, electron microscopes also experienced rapid development in China.
Nowadays, 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. Therefore, we can directly observe the atomic conditions in metals and the neat arrangement of atoms in semiconductors through electron microscopes.
The resolution of electron microscopes is still far superior to that of optical microscopes. The large magnification of optical microscopes is about 2000 times, while modern electron microscopes have a magnification of over 3 million times. Therefore, through electron microscopes, it is possible to directly observe the neatly arranged atomic lattice of certain heavy metal atoms and crystals (note that only the arrangement can be seen, and the atomic structure and molecular level cannot be clearly seen by electron microscopes. What can be seen under the microscope is the crystal shape of molecules with different configurations)
At present, microscopes are basically unable to see molecules clearly, not because the magnification is insufficient, but because the resolution of optical microscopes cannot be achieved. The current high resolution STORM is around 20nm, which means that two points separated by more than 20 nanometers can be seen clearly, while those below 20 nanometers appear as a cluster.
Molecules are at least at the nanoscale. If we use electron microscopy, it's hard to say. The magnification of electron microscopy can already reach 10000 times, and the resolution of electron microscopy is at the nanoscale. At the same time, I want to tell you that resolution is very important. If the resolution cannot be reached, high magnification is useless.
