The solar system model of atoms was created in the early 2000s by the famous physicist Ernest Rutherford, who led the design of Rutherford scattering experiments, using alpha particles to probe the structure of atoms. They fired alpha particles at gold leaf paper, which was only a few atoms thick, and found that the vast majority of the particles would pass straight through the gold leaf, but there were individual particles, about one in every 8,000, that would change direction by more than 90°. Since alpha particles are positively charged, Rutherford concluded that most of the region within an atom is empty, like the solar system, so most particles will pass straight through, and the center of the atom is concentrated in a small area of most of the mass and positive charge of the atom, that is, later called the nucleus, and individual alpha particles encounter the same positively charged nucleus, are bounced out, and the direction will change greatly. He also calculated that the radius of an atomic nucleus is at least one-third smaller than one-third of an atom. Rutherford thus proposed a model of the solar system of atoms: positively charged nuclei resemble the sun, negatively charged electrons resemble planets orbiting the sun, and unlike the solar system, the force that governs them is not gravity, but electromagnetic force.
With the development of quantum mechanics, scientists have realized that particles have wave-particle duality, and according to the uncertainty principle, the position and momentum of particles cannot be determined at the same time, which is the intrinsic property of all wave-like systems. So although the electron moves at high speed around the nucleus, it is not the circumferential or elliptical motion of the planet, but randomly appears somewhere around the nucleus, and we have no way to get the accurate position and speed of the electron at a certain time at the same time, we can only depict the probability of the electron appearing somewhere around the nucleus. We can imagine using a hypothetical camera to constantly take pictures of atoms, each photo records the position of the nucleus and electrons at a certain moment, and all the photos are overlapped together to form a randomly distributed electron cloud image, which is the electron cloud model of the atom, which has been generally accepted by the majority of scientists.
With the advent of electron microscopes and scanning tunneling microscopes, people can already scan and even control individual atoms, some scientists have arranged hernia atoms into the English word IBM, and IBM Research researchers have even made the world's smallest micro-film "A Boy and His Atom" (attached) by arranging atoms.
Even so, the atoms in the images obtained by the scientists were still just small, fuzzy spots. A few years ago, Ukrainian scientists finally captured an electron cloud image of carbon atoms through an improved field-induced emission microscope, just like the textbooks. At this point, the atomic solar system model seems to have officially declared its end, and the electron cloud model has entered the shining scientific stage.
(The electron cloud images of carbon atoms taken by field-emitting microscopes are the same as in textbooks.) ）
But slowly, what we've observed with these new technologies is still only the atomic structure at the atomic level, such as the cloud of carbon atom electrons shown in the figure above, which is still only an extremely blurry image. Just like looking at a star system at great distances with a Hubble telescope, it is simply impossible to see the planets orbiting it. The understanding of atomic systems still needs to be completed by more advanced techniques and experiments. Time, may be the most important parameter for correctly understanding the real model of atoms, see my other two articles: "The universe may just be an elementary particle in the large particle collider", "Time constant, the ultimate key to unlocking the mysteries of the universe?" 》
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In A Boy and His Atom (video from the Web), IBM researchers synthesized a 242-frame animated film using a two-ton scanning tunneling microscope that controls a microscopic needle to precisely move atoms on the surface of copper in an environment of minus 268 degrees Celsius.