Explanation

The first group of metal elements in the periodic table with atomic number 26, atomic weight 55.845, and element symbol Fe. The common chemical valences are+2 and+3. The theoretical density at room temperature is 7.875g/cm3. melting point 1538 ° C. Iron has solid polymorphic transformation. Iron also has magnetic transformation, ferromagnetism below 770 ° C, paramagnetism above 770 ° C transformation; Y Iron is non-magnetic. pure iron has good ductility and magnetic properties; Soluble in dilute sulfuric acid, hydrochloric acid, and nitric acid, but insoluble in concentrated sulfuric acid. The abundance of iron in the crust is about 5.6%, second only to oxygen, aluminum and silicon, and most of it exists in the form of iron bearing minerals. Iron is the most important, widely used and cheapest metal in modern industry. iron has been used for more than five years.

Classification