Question

The chemistry of lithium is very similar to that of magnesium even though they are placed in different groups. Its reason is that:
A.both are found together in nature
B.both have nearly the same size
C.both have similar electron configurations
D.the ratio of their charge to size is nearly the same

Answer 1

Hint: The elements in periodic tables are arranged in a way that every element of each group shows similar physical characteristics and chemical characteristics. But due to some opposite trends of periodic properties from left right and top bottom, there are some similarities observed between two different group elements.

Complete step by step answer:
-According to periodic properties of the elements of second period ( Li, B, Be) and third period (Mg, Al, Si) elements which are diagonally present with each other in the periodic table, show some similar kind of chemical properties. For example, formation of nitrides, halides. . this kind of similarity of their properties is called diagonal relationship.
One of the examples of diagonal relationship is,
- Lithium from the second period of group 1 and Magnesium from the third period of group 2 forms carbonates which dissociates and forms carbon dioxide. Like Magnesium, lithium also reacts directly with nitrogen and forms nitrides.
-This is because the ratio of their charge to size is nearly the same. Because from left to right size increases but top to bottom size decreases. Due to these opposite trends of size from left right and top bottom, the ratio of charge to size of lithium and magnesium is nearly the same.

So, the correct option is D.

Note:
This kind of similarity is because the left to right or top to bottom of a group shows opposite effects of periodic properties. As well as due to the small size and high charge density of Lithium , Boron, Beryllium they show this kind of unusual behavior.