Any child knows that metals are attracted to magnets. After all, they often hung magnets on the metal door of the refrigerator or letters with magnets on a special board. However, if you attach a spoon to a magnet, there will be no attraction. But the spoon is also metal, why then does this happen? So let's find out which metals are not magnetic.
Scientific point of view
To determine which metals are not magnetized, you need to find out how all metals in general can relate to magnets and a magnetic field. In relation to the introduced magnetic field, all substances are divided into diamagnets, paramagnets and ferromagnets.
Each atom consists of a positively charged nucleus and negatively charged electrons. They are constantly moving, which creates a magnetic field. The magnetic fields of the electrons of one atom can reinforce each other or destroy, depending on the direction of their movement. Moreover, they can be compensatedbe:
- Magnetic moments caused by the motion of electrons relative to the nucleus are orbital.
- Magnetic moments caused by the rotation of electrons around their axis - spin.
If all magnetic moments are equal to zero, the substance is referred to as diamagnets. If only spin moments are compensated - to paramagnets. If the fields are not compensated - to ferromagnets.
Paramagnets and ferromagnets
Consider the case when each atom of matter has its own magnetic field. These fields are multidirectional and compensate each other. If a magnet is placed next to such a substance, then the fields will be oriented in one direction. The substance will have a magnetic field, a positive and a negative pole. Then the substance will be attracted to the magnet and itself can be magnetized, that is, it will attract other metal objects. So, for example, you can magnetize steel paper clips at home. Each will have a negative and a positive pole, and it will even be possible to hang a whole chain of paper clips on a magnet. Such substances are called paramagnetic.
Ferromagnets are a small group of substances that are attracted to magnets and easily magnetized even in a weak field.
Diamagnets
In diamagnets, the magnetic fields inside each atom are compensated. In this case, when a substance is introduced into a magnetic field, the motion of electrons under the action of the field will be added to the proper motion of electrons. This movement of electrons will causeadditional current, the magnetic field of which will be directed against the external field. Therefore, the diamagnet will weakly repel from the nearby magnet.
So, if we approach the question of which metals are not magnetic from a scientific point of view, the answer will be diamagnetic.
Distribution of paramagnets and diamagnets in Mendeleev's periodic system of elements
Magnetic properties of simple substances change periodically with increasing element number.
Substances that are not attracted to magnets (diamagnets) are located mainly in short periods - 1, 2, 3. Which metals are not magnetized? These are lithium and beryllium, while sodium, magnesium and aluminum are already classified as paramagnetic.
Substances attracted to magnets (paramagnets) are located mainly in the long periods of the periodic system of Mendeleev - 4, 5, 6, 7.
However, the last 8 elements in each long period are also diamagnets.
In addition, there are three elements - carbon, oxygen and tin, the magnetic properties of which are different for different allotropic modifications.
In addition, 25 more chemical elements are named, the magnetic properties of which could not be established due to their radioactivity and rapid decay or difficulty in synthesis.
Magnetic properties of lanthanides and actinides (all of them are metals) change irregularly. Among them there are both para- and diamagnets.
They produce special magnetically ordered substances - chromium, manganese, iron, cob alt, nickel,whose properties change irregularly.
Which metals are not magnetic: list
Ferromagnetics, that is, metals that are well magnetized, there are only 9 in nature. These are iron, cob alt, nickel, their alloys and compounds, as well as six lanthanide metals: gadolinium, terbium, dysprosium, holmium, erbium and thulium.
Metals that are attracted only to very strong magnets (paramagnets): aluminum, copper, platinum, uranium.
Since there are no such large magnets in everyday life that would attract a paramagnet, and there are no lanthanide metals, we can safely say that all metals, except for iron, cob alt, nickel and their alloys, will not be attracted to magnets.
So, which metals are not magnetic to a magnet:
- paramagnets: aluminum, platinum, chromium, magnesium, tungsten;
- diamagnets: copper, gold, silver, zinc, mercury, cadmium, zirconium.
In general, we can say that ferrous metals are attracted to a magnet, non-ferrous metals are not.
If we talk about alloys, iron alloys are magnetic. These include primarily steel and cast iron. Precious coins can also be attracted to the magnet, since they are not made of pure non-ferrous metal, but of an alloy that may contain a small amount of a ferromagnet. But jewelry made of pure non-ferrous metal will not be attracted to a magnet.
Which metals don't rust or magnetize? These are ordinary food grade stainless steel, gold and silver items.
