Why are there only magnets that attract iron, but not gold, silver, or copper?
Magnets are one of the more common items in everyone’s daily life. It is estimated that many friends have had this question, that is why there are only magnets that can hold iron, but no magnets that can hold gold, silver, copper, and aluminum. , Magnetic silver, magnetic copper and magnetic aluminum? To solve this question, we need to briefly discuss the principle of magnetism. Principle of magnetism According to the different conditions under which magnetic objects generate magnetic fields, they can be divided into two categories, one is permanent magnetic objects, and the other is electromagnetic objects. The black magnets we usually see belong to permanent magnets; and the metal coils will show certain magnetism after being energized. After the current disappears, the magnetic field disappears, so this kind of object is electromagnetic. Also called soft magnetic. Whether it is a permanent magnetic substance or an electromagnetic object , according to Maxwell's equation, the ge...