Question

The similarity between Li to group 1 and Mg of group 2 is called a diagonal relation. It arises because
A. Li and Mg atoms have similar sizes
B. Li ad Mg ions have similar sizes
C. Li and Mg have similar sizes
D. all of these

Answer 1

Correct Answer - D
On descending a group, the atoms and ions increase in size. On moving from left to right in the periodic table, the size decreases. Thus, on moving diagonally, the size reains nearly the same:
`r(Li)=152pm,r(Mg)=160pm`
`r(Li^(+))=76pm,r(Mg^(2+))=72pm`
Similarly, on moving diagonally, the electrongetivities remains nearly the same.
`{:(Li,Be),(1.0,1.5),(Na,Mg),(0.9,1.2):}`