Which of the following metal has the highest melting point
Li
Na
K
Cs
As we learnt in
Physical properties of alkali metals -
1. Silvery white
2. Soft in nature, can be cut with knife except Li
3. Highly reactive, kept in solution to prevent reaction with air
-
As charge density decreases down the group of Alkali metals, the strength of the metallic bond also falls, thus, lowering the melting points.
Therefore, Li has highest melting point.
Option 1)
Li
This option is correct
Option 2)
Na
This option is incorrect
Option 3)
K
This option is incorrect
Option 4)
Cs
This option is incorrect