Q. Atomic mass of an element?

The number at the bottom of every square in the periodic table is the atomic mass of that element in amu. A scan of the periodic table will without delay tell you that the atomic masses of many elements are not whole numbers. The reason for this is that several elements occur in nature as a mixture of isotopes-isotopes with different masses. The atomic mass of an element specified in the table is a weighted average of the atomic masses of the naturally occurring isotopes of the element. This weighted average takes in to account the mass and abundance of each of the isotopes. The following instance Problem shows you how to calculate the atomic mass of an element.