Question

Arrange the following calcium species in terms of increasing size:
$Ca,{Ca}^{+},{Ca}^{2+},{Ca}^{3+},{Ca}^{-},{Ca}^{2-}$

• A. ${Ca}^{3+},{Ca}^{2+},{Ca}^{+},Ca,{Ca}^{-},{Ca}^{2-}$
• B. ${Ca}^{3+},{Ca}^{+},{Ca}^{2+},Ca,{Ca}^{-},{Ca}^{2-}$
• C. $Ca,{Ca}^{+},{Ca}^{2+},{Ca}^{3+},{Ca}^{-},{Ca}^{2-}$
• D. None of the above
  

Answer 1

The correct option is A ${Ca}^{3+},{Ca}^{2+},{Ca}^{+},Ca,{Ca}^{-},{Ca}^{2-}$

Since anions are larger than the corresponding neutral atom formed by the addition of the electrons, adding electrons increases the number of electron-electron repulsion interactions that take place. Cations are smaller than the corresponding neutral atoms formed by the loss of electrons, since the valence electrons, which are furthest away from the nucleus, are lost.Greater the charge on the cation smaller it is while greater the charge on the anion larger it is.So in $Ca$ atom $+3<+2<+1<Ca<-1<-2$