Fire is a special phenomenon, and fires of different temperatures can have different effects. A fire with a lower temperature can give people a warm feeling, and a fire with a temperature exceeding a certain scale will make people feel a burning sensation. If the flame continues to heat up at this time, it will trigger a chemical reaction of organic matter, which intuitively shows that the human skin is burning. The power of fire is not only in burning organic matter, but also in that it can instantly turn cold metal into "flowing water".
Friends who have been exposed to middle school physics knowledge should know that any metal has a certain melting point. This melting point refers to the turning point at which an object changes from a solid state to a liquid state, and most metals are solid at room temperature, and the possibility of becoming a liquid state increases as the temperature continues to rise. After research, it was found that the melting point of iron is 1538 degrees Celsius. If the magnet is heated with a temperature exceeding this melting point, what will happen to the magnet?
Before understanding the above problems, we first need to understand why magnets are magnetic. Under normal circumstances, most substances are not magnetic, which starts with the basic unit that constitutes matter - the atom. An atom is composed of a nucleus and extranuclear electrons. There are positively charged protons in the atomic nucleus, while the electrons are negatively charged. The electrical properties of the two cancel each other out, so the atom is neutral. In addition to being negatively charged, electrons are also magnetic, but in most atoms, the electrons are arranged in such a disorganized order that their magnetic effects cancel each other out.
The reason why a magnet has magnetism is that the electrons in the atoms are arranged neatly under the influence of external factors, so that the magnetism is all in the same direction, so that the magnetism will not cancel but strengthen. Metals such as iron, nickel, and cobalt can all be turned into magnets, and the electrons inside them are aligned to form a spontaneous magnetization region, which is called a "magnetic domain". If you want to make the magnet lose its magnetism, you must destroy the internal magnetic domains. The main method at present is to apply high temperature.
In nature, iron is relatively less, and more is iron oxides, of which the naturally formed magnet is ferric tetroxide. This compound is the main component of ferromagnetic ore, and because of its gray-black color, natural magnets look gray-black. After research, it was found that the melting point of ferric oxide is 1594.5 ° C, in other words, as long as the natural magnet is heated to this temperature, it will melt. So in addition to the molten magnet becoming a pool of liquid, is its magnetism still there?
The Curie point of magnets of different materials is different, and the Curie point of magnets is between 480 and 550 degrees Celsius. The Curie point of a magnet is a range because there are many types of magnets with different compositions of iron oxides. So it is certain that when the magnet melts, it becomes a liquid, and that liquid has lost its magnetism.
After understanding why magnets have magnetic problems, this problem is not difficult to understand. According to the laws of thermodynamics, basic particles such as molecules and atoms will become active when the temperature rises. Among them, the active phenomenon of gas molecules is the most obvious, and the active phenomenon of solid atoms is the least obvious. Sexual changes, we are also difficult to see from the surface of the object. Taking this magnet heating as an example, the atoms in the magnet will undergo thermal motion after being heated.