Magnets have an influence on all metals without exception. But there are three situations. Based on this, metals can be divided into three types: paramagnets, diamagnets, and ferromagnets.
Paramagnets: Slightly attracted by magnets.
Diamagnets: Slightly repelled by magnets.
Ferromagnets: Strongly attracted by magnets.
There are only three ferromagnets: iron, cobalt, and nickel. The rest are either paramagnets or diamagnets. There are also their alloys, and their magnetic natureis closer to ferromagnets to varying degrees depending on the content.
Stainless steel containing nickel can be (strongly) attracted by magnets. Stainless steel without nickel (usually containing chromium) has a weak reaction to iron and is not easily noticeable. The latter has a higher hardness due to the presence of chromium. The former is what is commonly known as stainless iron.
Suspend aluminum and copper with long thin threads and keep them stationary without swinging. Slowly approach aluminum or copper laterally with a magnet, and it can be found that they will be slightly attracted or repelled. So they are respectively paramagnets and diamagnets.
The scientific name of a magnet is lodestone.
A magnet is a type of magnetic body.
Magnets can attract metals such as iron, nickel, and cobalt and are commonly known as lodestones. They can be divided into common permanent magnets and electromagnets that have magnetism only when energized. If a magnet is made into a rod or needle shape and suspended, it will naturally point to the south and north poles of the earth. Magnets are divided into large magnets and small magnets.
Large magnets: Magnets have very common uses. Using electromagnets, cranes for transporting steel are made. When energized, they become magnets with huge magnetism and can thus attract heavy steel. When unloading the steel, it is only necessary to cut off the power supply.
Small magnets: Compared with large magnets, compasses appear small and light, and their magnetism is much weaker. The function of a compass is not to attract iron but to reflect the earth's magnetic force.
The property by which magnets attract substances such as iron, cobalt, and nickel is called magnetism. The regions with strong magnetism at both ends of a magnet are called magnetic poles, one end is the north pole (N pole), and the other end is the south pole (S pole). Experiments show that like magnetic poles repel each other, and opposite magnetic poles attract each other.
There are many elementary magnets with two opposite magnetic poles in iron. When there is no external magnetic field, these elementary magnets are arranged in disorder, and their magnetism cancels each other out and does not show magnetism externally. When iron is brought close to a magnet, under the action of the magnet, these elementary magnets are neatly arranged, so that the end close to the magnet has a polarity opposite to that of the magnet and is attracted. This shows that due to the presence of elementary magnets, iron can be magnetized by a magnet. However, metals such as copper and aluminum do not have an elementary magnet structure and therefore cannot be attracted by magnets.
