In life, we often hear some physical nouns, such as molecules, atoms, quantum, etc. We are both unfamiliar with these words, and today we will find out.
Quantum
In modern physics, all particles with quantum effects cannot be used to infer and understand their behavior based on the cognition of the macroscopic world, so physicists call this particle a quantum particle. In the above introduction, we can see that the word quantum appears frequently, so what is quantum? First of all, we need to make it clear that quantum does not refer to alone, but a unit. Initially, when Planck studied bold radiation, he found that light was discrete in the form of a small part of energy, which was called quantum. The original meaning of the word quantum is packaged and discrete. There was once a saying that no matter how big the lie you tell, quantum mechanics can help you get back seamlessly. From this we can see how magical the mechanics of quantum is. Under the basic unit of quantum, there are many particles, and their sizes are very different. Let us understand it.
Image from the network
atom
Let’s talk about atoms first. It can be said that most things in the world are composed of atoms. That is, the pens, paper, chairs, cups around us, to clouds, water, ice, or the larger and farther away from us, the sun, the moon, Andromeda, the centaur, and you and me, without exception, are all made up of those tiny atoms. Not only that, the most destructive weapon created by humans, the atomic bomb, works the principle of its working is the separation of nucleons and electrons inside atoms.
When we were in junior high school, we all learned the internal structure of atoms and knew that it was electrically neutral, that is, it contained positively charged substances in it. This substance is the heavyweight player in the atom - the atomic nucleus. There are two reasons why it is called this: one is that its mass accounts for most of the entire atom, which is in fact true, and the other is that it is the core of the atom, located in the center of the atom, and surrounding it is surrounded by electrons that are constantly moving. Electronics are not irregular, they extend the energy level (in order to understand the energy level more vividly, we can regard the energy level as a rail, and electrons are like trains driving on tracks). In addition, electrons are negative charges and can be attracted by positive charges.
Although it doesn’t take long for us to know atoms, the process of human understanding of atomic structure is like a blind man moving forward carefully in the darkness and going through a long time. In 1803, the first atomic structure model in human history was born, which was a solid model proposed by Dalton. This model has many problems and cannot reasonably explain some phenomena.
So, the second model was born: in 1904, Joseph John Thomson believed that the atom was a positively charged ball, and electrons were embedded in it, like a round biscuit containing raisins. Compared with the first model, this model has made a lot of improvements, but there are still some details that are not satisfactory.
Until 1911, a man named Lutherf bombarded gold foil with alpha particles and proposed a classic model - the planetary model. Several models after that were all obtained by slightly changing the planetary model. As the name suggests, the planetary model is to regard the internal structure of atoms as the solar system. The sun is the nucleus. Due to gravity, the Earth, Mercury, Venus, etc. surrounding the sun are all electrons. This model, which almost perfectly presents the internal structure of atoms, is undoubtedly a miracle for physics, and has greatly promoted the development of physics. Later, his student Boer added energy levels to the planetary model, and electrons moved at the energy levels. We will talk about so much about the history of the development of atomic structural models for the time being.
Protons and neutrons
Next, let’s talk about protons and neutrons. The nucleus is composed of a combination of protons and neutrons. The protons have a positive charge, but the neutrons are not charged. According to the foregoing, electrons carry negative charges, so a proton attracts an electron. Putting this sentence on the atomic level means that in an atom, if there is no other situation, the number of protons should be equal to the number of electrons.In daily life, we have more or less heard the word neutron star. This is when a star collapses inward from gravity, it produces extremely high temperatures, which causes electrons, protons and neutrons in the atom to separate from each other. The separated electrons and protons constantly form neutrons, and neutrons support themselves with the Pauli incompatibility principle, so they can compete with gravity. The collapse ends, and the stars also become neutron stars with extremely dense and all composed of neutrons. This passage doesn't matter because we're off topic.
Go back to the topic, after reading this, you may think, since the nucleus is composed of atoms and protons, what are protons and neutrons composed of? Have scientists discovered substances smaller than protons, neutrons and electrons?
quark
In fact, in order to find the answers to these two questions, scientists once wanted to blow away the protons, but failed. They found that during the bombardment of the proton, three scattering angles appeared on the proton, which also determined that the proton consisted of three smaller particles: two upper quarks and one lower quark. At that time, people once thought that quarks were the basic substance that made up all things, so they called it basic particles. But now, the concept of "essential particles" is gradually becoming indifferent to people because people think that elementary particles may also be composed of some unknown smaller particles. Note here that quarks are a type of particles. Under this type, it is divided into six categories according to its own energy and rotation angle. Each category is called one, namely upper quark, lower quark, charm quark, strange quark, top quark, and bottom quark.
strong interaction
OK, let's continue. If you know that protons are composed of quarks, then you may guess what quarks are composed of? To answer this question, we must first bombard individual quarks, but unfortunately, all quarks in nature appear in collective form. The current technological level of human civilization is not enough to separate unit quarks from collective. This is the confinement and strong interaction of quarks. We can't help but have a question, why is it impossible to have a single quark in nature? To answer this question, we must first understand strong interactions. It can be said that between one quark and another, there is a rubber rope connecting them together, and this rubber rope is a manifestation of strong interaction. When the two quarks are very close, the rubber rope will not be subjected to force, so the two quarks can move freely, but if the two quarks are very far away, the rubber rope will begin to be subjected to force, pulling the two quarks back with its own elastic force, and this power is very powerful. It is precisely because of this that it is difficult for humans to separate a single quark.
hastior
, etc., have we forgotten something? Yes, we don't know what neutrons are composed of. Although as mentioned earlier, protons and electrons form neutrons, this is only in special cases. Normally, protons are composed of two lower quarks and one upper quark, exactly opposite to protons. After meeting Quark, let’s get to know Qiangzi, Baryson and Meson again. Hadron is a subatom, like quarks, and is also the name of a particle species. Under a hastener, it can be divided into baryons and mesons (note that here means that a hastener contains baryons and mesons, rather than a baryon and meson to form a hastener). Barons are also a general term for a type of particles. Protons and neutrons belong to baryons. In addition to them, seeds also include many particles, which will not be explained in detail here. Meson is a boson used to transmit strong interactions between nucleons. (To explain, nucleons are the collective name of protons and neutrons) The strong interaction here, that is, the interaction between nucleons, is different from the strong interaction between quarks mentioned above, and we will explain it in detail later.
molecule
said so much, but I forgot about a very important particle, molecule. It consists of two or more atoms, and there are several special features: one is that there are spacings between molecules, and the other is that all molecules that make up matter will never stop and move irregularly. The higher the temperature, the faster the molecules diffuse. This is called the thermal motion of molecules.For example, when we use a hair dryer to wet our hair, the hot air blown by the hair dryer causes the hair temperature to rise. The reason why the hair is wet is because there are water molecules. The increase in hair temperature will trigger the heat movement of the molecules and cause the water molecules to continue to spread around, and eventually the hair will dry. What we are going to say is very important. Molecules have volume and mass. Because of this, you and I have height and weight. Last point, the molecular properties of the same substance are the same, but the molecular properties of the substance are different, which shows that the DNA of our humans and ants is different.
