Most common alloys are that of transition elements as they have which of the following?

Nearly same atomic sizes

The correct answer is: (3) Nearly the same atomic sizes

Most common alloys are those of transition elements because they have nearly the same atomic sizes. Transition metals often have similar atomic radii due to their comparable electron configurations and similar numbers of valence electrons. This similarity in atomic sizes allows the atoms of different transition metals to pack together closely in the crystal lattice, facilitating the formation of solid solutions or alloys with homogeneous structures. This feature is essential in achieving good mechanical properties and solid-state diffusion in the alloy, making them widely used in various engineering and industrial applications.