Question

The correct order of boiling point of $K,Ca,Sc$ is:

• A. $K>Ca>Sc$
• B. $Ca>K>Sc$
• C. $Sc>Ca>K$
• D. $K>Sc>Ca$

Answer 1

The correct option is C $Sc>Ca>K$

As the number of mobile electrons increases, strength of metallic bonding increases and as a result boiling point also increases. The number of mobile electrons will be more in transition metal $\left(Sc\right)$ than alkaline earth metal $\left(Ca\right)$ than in alkali metal $\left(K\right)$. Hence the correct order of boiling point is $Sc>Ca>K$.