Answer: the number of neutrons present in a single [tex]Fe^{2+}[/tex] atom is 30
Explanation: Given atom is [tex]Fe^{2+}[/tex] which is basically ion of iron from which two electrons have been removed .
Thus Atomic number of [tex]Fe^{2+}[/tex] , Z = 26
Mass number of [tex]Fe^{2+}[/tex] , M=56
Now we know that the mass number of the atom (M) is equal to the sum of the number of protons(P) and neutrons(N) in the nucleus ,i.e., M=P+N ----(A)
Also the number of protons in the nucleus of the atom is equal to the atomic number (Z).
Therefore number of protons , P=Z= 26
Using equation (A) we get
56=26+ N
=>N=30
Thus the number of neutrons present in a single [tex]Fe^{2+}[/tex] atom is 30
