In: Chemistry
Select best choice and breifly explain your answer.
1. Smallest Radius? Sc Ti V
2. Greatest Volume S2- Ar Ca2+
1. V is having the smallest radius among the three. This is a periodic property. The more protons added to the nucleus in the same row, the radius gets shorter because stronger attraction between the nucleus and electrons.
The order of radius is Sc > Ti > V
2. S2- Ar Ca2+ these three are isoelectronic with Ar but S2- has two extra electrons in its outer most shell than the number of protons in the nucleus, therefore the attraction between nucleus and external electrons will be less. Also, there would be repulsion among the electrons due to excess in number. So the radius will be more, consequently the greatest volume will be for S2-.
For Ca2+ the opposite effect will reduce the radius and volume. More protons in the nucleus compare to number of electrons in the external shell. Ar has equal number of protons in the nucleus and electrons in the outer shell.
The order of volume is - S2- > Ar > Ca2+