What about magnets?

The composition of the magnet is iron, cobalt, nickel and other atoms, the internal structure of its atoms is relatively special, and it has a magnetic moment. Magnets can generate magnetic fields and have the characteristics of attracting ferromagnetic substances such as iron, nickel, cobalt and other metals. Magnet type 1, shape type magnet. Block magnet, tile magnet, shaped magnet, cylindrical magnet, ring magnet, disc magnet, magnetic bar magnet, magnetic rack magnet. 2, attribute magnets. Samarium cobalt magnet, NdFeb magnet (strong magnet), ferrite magnet, aluminum nickel cobalt magnet, iron chromium cobalt magnet. 3, industry magnets: magnetic components, motor magnets, rubber magnets, plastic magnets and so on. 4, the magnet is divided into permanent magnet and soft magnetic, permanent magnet is plus strong magnetic, so that the spin of the magnetic substance and the angular momentum of the electron are arranged in a fixed direction, soft magnetic is plus electricity. Extended data: The magnet is a natural magnetite. The ancient Greeks and Chinese found in nature a naturally magnetized stone, called "magnet." The stone can magically pick up small pieces of iron and always point in the same direction when swung at will. Early seafarers used the magnet as their first compass to navigate the sea. The earliest discovery and use of magnets should be the Chinese, that is, the use of magnets to make a "compass", is one of China's four great inventions. After thousands of years of development, today magnets have become a powerful material in our lives. By synthesizing alloys of different materials, the same effect can be achieved with magnets, and the magnetic force can also be improved. Artificial magnets appeared in the 18th century, but the process of making stronger magnetic materials was slow until the 20th century.