If the metal is melted, density of the molten metal was found to be 3 g/cc. What will be the percentage of empty space in the melt?

Question

Paragraph: Calcium crystallizes in a cubic unit cell with density 3.2 g/cc. Edge-length of the unit cell is 437 picometre (pm). 

If the metal is melted, density of the molten metal was found to be 3 g/cc. What will be the percentage of empty space in the melt? 

(A) 31% 

(B) 36% 

(C) 28% 

(D) 49% 

Answer 1

Correct option  (A) 31%

Explanation:

 In fcc packing efficiency = 74%

Let’s say total volume of the solid = V

Mass = (3.2) V

Now, after melting, mass would be same. 

So, final packing efficiency 

Hence empty space ~ 31%