Question

The atomic radius of $Ag$ is closed to
A. $Cu$
B. $Hg$
C. $Ni$
D. $Au$

Answer 1

Hint: The atomic radius of a chemical element is generally used to measure the size of its atoms and represented by the mean or general distance from the center of the nucleus to the boundary of the surrounding shells of electrons or we can say that from nuclear to outermost shell of the electrons.

Complete Solution :
 Atomic radius is categorized into three types of radius known by the name Van der Waals radius, ionic radius and covalent radius. Variation of atomic radii in periodic table can be explained as, the radii generally decrease along each period or we can say each row of the table i.e. from the alkali metals to the noble gases and increase down each group column.
- As we know that the atomic radius of the second and third transition series are almost the same. This phenomenon can be explained on the basis of intersection of the 4f orbitals which must be filled before the 5d series of elements begin. The filling of 4f before 5d orbitals results in a regular decrease in radii due to contraction called Lanthanoid Contraction. So we can say that the atomic radius of Ag is closest to Au. So, the correct answer is “Option D”.

Note: The trends of the atomic radii can be explained in the way that the atomic radii decrease across the periods due to the increase in atomic number which increases the effective nuclear charge towards the outermost electrons increases and atomic radius decreases. On moving down the group atomic radii increases due to an increase in the number of shells.