Back in the 18th century, during the time of Lomonosov, physicists performed some strange experiments in social settings. A gentleman is lying on a glass table. The scientist stands on a small glass stool, holds the hand of the lying man with one hand, and places the other hand on the disc of the generator. A lady, encouraged, put her finger close to the man’s forehead. Sparks crackled between the fingers of the gentleman and the lady. The lady screamed and quickly retracted her fingers.
People ask scientists what this is all about, and scientists just say something vague about “electricity” or something. These words explain nothing.
The mysterious “electricity” behaves like real ghosts: it makes people’s hair stand on end, it runs through people’s bodies in a way that makes people feel like crawling over ants, and even the most courageous people can’t help but want to die. tremble. If people hold hands, the trembling goes on in succession—from the first person to the last.
These were signals from the atomic world, but people did not understand these signals at that time. Only Lomonosov, who was ahead of his time, knew that the principle of electricity should be found in the atomic world.
In 1802, in the laboratory of Russian physicist Petrov, arc lamps emitted brilliant light. Decades later, the streets of the city were illuminated by the “light of Russia” – Yablochkov candles.
The first Rhodes King bulb appeared, in which an electric current caused a small block of carbon to emit light.
Later, it was discovered that electric current can not only make the carbon block or carbon filament in the bulb glow, but also make the air glow.
Lomonosov has done such an experiment: he took out the air in a glass ball, and then charged the glass ball with friction. The electricity makes the thin air remaining in the glass bulb glow.
After 100 years, physicists repeated these experiments. But what exactly are these phenomena? How did they happen? There are no answers to these questions in the book.
In order to find the answer, scientists conduct experiments one after another. They tried to bring the magnet close to the discharge tube. To their surprise, the green part of the glass moved and changed its position.
Light is attracted by magnets!
However, you know that many other experiments have repeatedly proved that light is not deflected by the influence of magnetism.
From this we can see that it is some real substance that hits the wall of the tube through the glass tube and makes the glass glow.
It became more and more obvious that the electric current was not a mysterious supernatural force, but a torrent of invisible tiny particles.
These particles, these “atoms of electricity” should be given a name. Scientists remembered that the word “electricity” comes from the Greek word “amber”, because the earliest experiments with electricity were done with amber. They decided to use “amber” to call “atoms of electricity” (electrons).
Not long after, even more astonishing news came from the atomic world.
In 1895, the scientist Roentgen noticed that the discharge glass tube not only emits visible light, but also emits certain invisible rays. This ray penetrated the black paper Roentgen used to wrap his photographic negatives. After processing, dark shadows appeared on the photographic film.
Scientists have learned yet another thing that previously seemed inexplicable. They found that the invisible rays were emitted from the part of the glass tube wall that was struck by the electrons.
They set up a metal plate as a target on the way the electrons in the glass tube passed. This piece of metal also begins to emit invisible rays under the impact of electrons.
The rays were emitted from the atoms, but no one knew at that time how the atoms were changed by the shooting of the electrons.
After a few months (now measured not in centuries but in years and months), a new signal came from the depths of the atom. The physicist Becquerel took a photographic negative and wrapped it in black paper, and put a little uranium salt on it. After he developed the negative, he found that the negative had turned black.
Something emanates from the uranium atoms, and it passes through the paper and hits the photographic plate. The blow was so powerful that it shattered the silver bromide coated on the photographic film. The silver bromide particles decompose into bromine and silver.
It’s really like fantasy. Energy can seem to be created out of nothing!
But is it really born from “nothing”? No, nothing does not come into being. Radiation is emitted from atoms.
So what exactly is emitted from the atom? It has to be figured out. Magnets helped scientists again. The messengers running from the atoms are divided into three strands in the magnetic field.
Straight ahead is an invisible ray, much like a Roentgen ray. Magnets have no effect on it because it is light, although invisible to the naked eye. Light is not deflected in a magnetic field. Scientists call these rays gamma (γ) rays.
Off to the left and right are tiny particles—crumbs of atoms. One stream of debris is electrons, also called beta (beta) particles. Another stream of debris is called alpha (α) particles.
Why do electrons and alpha particles emitted from radium go in two different directions? Because they carry different charges: electrons have a negative charge, and alpha particles have a positive charge. The particle flow formed by the movement of charged particles is affected by the magnet, and the direction is deflected.
The secret signal sent from the atom was thus deciphered by scientists.
For centuries, people have believed that atoms are indivisible and eternal. Now they suddenly saw that the unchanging, indivisible atom can change.
It’s as if you locked three nickels in a drawer. A few days later, you notice that there are not three nickels in the drawer, but two. The third nickel changed itself into threes and twos.