Question
Define atomic size or atomic radius of an element. Why is it not possible to determine its absolute value?
Solution
Assuming atom to be spherical, the distance between the nucleus and the outermost orbit of the atom is called the atomic radius of the element. However, it can not be determined precisely due to the following reasons:
(i) Atom is too small to be isolated.
(ii) According to the probability picture of electrons, an atom does not have a well-defined boundary.
(iii) The probability distribution of an atom is also affected by the presence of other atoms in its neighbourhood.
(iv)The size of the atom also changes from one bonding state to another.
Thus, it is not possible to determine the absolute value of atomic radius practically. In other words, atomic radius has no meaning.
