Is iron still magnetic under molten conditions i.e. in a hot liquid state ?

Without. Press Ann (?) Probably not this person), the magnetic properties of an object arise due to the accumulation of electromagnetic effects of a toroidal current formed by electrons revolving around a molecule.

All matter has this property, but because the molecular arrangement of objects is different, the magnetic field generated by the annular current of the molecules of many objects cancels each other out. The molecular arrangement of the magnet is very consistent, and the magnetic accumulation is enhanced, showing strong magnetism. At high temperatures, the movement of molecules becomes more violent, and their order is disrupted, so they no longer exhibit magnetism.

It's been a long time, and it's a bit messy, but that's what it means.

The ferromagnets we see today are compounds of iron or mixtures of iron and other substances, and although their properties are very similar to those of the geomagnetic field, they are definitely not the cause of the geomagnetic field. Because the experiments of the Curies proved that the magnetism of ferromagnetic matter completely disappears at a high temperature of 770 (Curie temperature). At high temperatures deep in the earth, iron reaches and exceeds its melting point and becomes liquid, and the Earth's magnetic field is never formed.

The French scientist Ampère revealed it more than a hundred years ago"The electrical nature of magnetic phenomena"In fact, people should have understood that the generation of the geomagnetic field must be intrinsically related to electrical phenomena.

According to the results of physical research, the electrons outside the nucleus of the atoms of matter in high temperature and high pressure will be accelerated and escape outward, so a large number of electrons will escape from the earth's core in the environment of high temperature of 6000K and 3.6 million atmospheres, and a negative electric layer will be formed between the mantle.

According to Maxwell's electromagnetic theory, it can be summed up in such a sentence: electric magnetism, magnetokinetic electricity. Therefore, in order to form the magnetic field of the north and south poles of the earth, it is necessary to form a rotating electric field, and the rotation of the earth will inevitably cause the rotation of the negative electric layer of the mantle, that is, the rotating negative electric field.

This is where the magnetic field comes in.

Concentrated sulfuric acid and concentrated hydrochloric acid can react with iron to quickly dissolve iron.

Sustained high temperatures (at least over 1500 °C) can also quickly melt iron into liquid.

Put the iron in concentrated nitric acid and heat it. They react to form ferric iron, which can also oxidize iron to form ferric. Due to heating, the reaction rate will be very fast, if hydrochloric acid is used, hydrochloric acid has no oxidation and can only produce divalent iron, which is not as fast as concentrated nitric acid.

In the process of melting iron into molten iron, only the state of iron changes, and no new substances are formed, which is a physical change. Food is easy to spoil, and it needs to be manifested by the chemical change of food spoilage, which belongs to the chemical properties of the substance. Bile alum is a blue crystal and does not need to go through a chemical reaction.

Iron belongs to crystals, and the melting point of pure iron is 1535, if there is solid iron in liquid iron, it means that it is in a solid-liquid coexistence state, so it is in the melting (or solidification) process at this time, so a is correct

Therefore, a

The melting point of iron is (1535 degrees Celsius).

Then the freezing point of liquid molten iron is (1535 degrees Celsius), and it has to (absorb heat) during the solidification process

But the degree of filial piety (the cover does not change).

When heated to a certain degree of heat, it loses its magnetism, and in fact, it is the "Curie point" of ferromagnetic matter.

Curie point": For any ferromagnetic substance, when the temperature is higher than this temperature, the ferromagnetism disappears completely and becomes an ordinary paramagnetic substance. The Curie point of various materials is different, it is one of the intrinsic parameters of magnetic materials, and it is only related to the chemical composition and crystal structure of the material.

There are special instruments for testing the Curie point of ferromagnetic materials, such as the Curie point tester (QS-CT type), and the university also talks about the test of testing the Curie point.

For example, the Curie points of iron, nickel, and cobalt are 1043 K, 631 K, and 1393 K, respectively, and K is the absolute temperature, which is equal to the temperature of +273 degrees Celsius.

The physical forms of matter are three-state, solid, liquid, and gaseous. The transformation between the three states of matter is a physical transformation, and the conditions for its transformation mainly depend on the temperature and pressure of the environment in which the substance is located. For example, at atmospheric pressure at standard sea level, water is converted between solid (ice) and liquid (water) at zero degrees Celsius, and between liquid (water) and gaseous (water vapor) at 100 degrees Celsius.

Therefore, the melting of iron into molten iron at high temperature is the transformation of physical form and physical properties.

Physical properties, or iron atoms.

This question cannot be asked in this way, and a condition should be added, in a standard environment.

Under standard conditions, the melting point of iron is 1538, and the condition for it to melt is that the temperature reaches at least 1538, and then it continues to heat. Melting absorbs energy and then destroys the intercrystalline energy to become a liquid state with less intermolecular energy, and when the temperature cannot be reached, the energy cannot be satisfied to cancel out the intermolecular energy, and they cannot move freely. At the melting point, the energy is equal, and he coexists in solid and liquid states.

The melting temperature is a range, the difference, this interval is called the melting range, it is the temperature difference between the beginning of melting and complete melting, but the melting point is fixed, it will begin to melt after reaching the melting point, and then the temperature will rise to complete melting.

Solids do not melt below the melting point!

Only after reaching the melting point, if the solid is heated again, the solid will melt!

No, although it will be affected by some environmental factors and its own impurities, the melting point is as high as it is. It's like the temperature of an ice-water mixture is 0 degrees.

What chemicals can melt iron without producing high temperatures.

The container of molten iron is called a graphite crucible, which has good high temperature resistance, and its melting point is higher than that of iron.

Graphite crucible has good thermal conductivity and high temperature resistance, and in the process of high temperature use, the thermal expansion coefficient is small, and it has certain anti-strain performance to quenching heat and quenching. It has strong corrosion resistance to acid and alkaline solutions and has excellent chemical stability. In metallurgy, casting, machinery, chemical and other industrial sectors, it is widely used in the smelting of alloy tools and the smelting of non-ferrous gold and alloys.

And it has a good technical and economic effect.

The internal energy increases during the melting of the crystal. During the endothermic melting of the crystal, the temperature does not change, but the internal energy increases. Reason:

The internal energy is increased by heat transfer, and heat transfer can absorb heat, but it is wary that when melting, the absorbed heat is not used to heat up, but to reduce the binding between molecules, that is, to increase the potential energy of molecules. Temperature is not the only factor that determines the magnitude of the internal energy of the object, when the volume or state of the object (or the number of molecules contained in the object) changes, the distance between the molecules changes, and the intermolecular forces change, which causes the change of the potential energy of the molecule, so the internal energy of the object also changes.

For example: when the ice reaches 0°, it begins to melt into 0° water. In this process, the temperature does not change and the internal energy increases.

Internal energy is divided into: molecular kinetic energy (depending on temperature) and molecular potential energy (depending on state) During melting, the kinetic energy of the molecule does not change, and the potential energy of the molecule increases, thus the total internal energy increases.