Atomic Mass of Iron

Iron is denoted by the symbol Fe. (Ferrum).    It belongs to Period 4 and Group 8 in the periodic table. It is grayish white in color with a specific gravity of 7.86.  Its atomic number is 26 and relative atomic mass is 55.85.  It exhibits variable valency  – 2 & 3.  

Introduction to atomic mass of iron

Atomic mass is the total number of neutrons and protons in the nucleus of the atom.  Atomic number is the total number of electrons or protons in an atom.  The electronic configuration is 2, 8, 14, 2.   The number of electrons in the atom is 26, which is equal to the number of protons. 

Atomic mass (A) = number of Protons (p) + number of Neutrons (n). 

Number of protons = number of electrons.

Atomic mass of iron = 26 + 29.85 = 55.85.

Atomic number of iron = 26

More about Atomic Mass of Iron

A close look at the electronic configuration of lighter elements reveals that those elements which had even number of protons, that is atomic number like 2He4, 6C12 etc. have their mass number twice their atomic number – except 4Be9 and 18Ar40.  Elements which have odd number of protons like 3Li7, 5B11 etc. have their mass number twice the atomic number + 1. (A = 2 Z +1) except 7 and 14 and 1H1.  This is not the case with heavier elements.  That is why iron, whose atomic mass is 26 does not have 52 as its mass number. 

Iron is not found in native state; it occurs only in combined state in its ore.  In this form, iron makes 5% of earth’s crust.  It is the second most abundant metal after aluminum.  

The ores of iron are red hematite (anhydrous ferric oxide) Fe2O3, brown hematite (hydrated ferric oxide) 2Fe2 O3. 3H2O, magnetite (triferric tetroxide) Fe3O4,  iron pyrites (iron disulphide) FeS2 and Siderite (ferrous carbonate) FeCO3. 

Iron is a heavy metal.  It is malleable and possesses high tensile strength.  It is a good conductor of heat and electricity.  It melts at 1535 degree Celsius.  It can be magnetized.