Question

sum of the fraction of total volume occupied by simple cubic and fcc​

Answer 1

Let the edge length of the cube be a and radius of atom be r.

Now, in simple cube, number of atoms present =  

8

1

​  

×8=1

So, volume occupied =1×  

3

4

​  

πr  

3

 

Now, in simple cube atoms at corners will be touching each other.

⇒a=2r⇒r=  

2

a

​  

 

Volume of cube =a  

3

 

So, fraction of total volume occupied =  

a  

3

 

3

4

​  

πr  

3

 

​  

 

=  

a  

3

 

3

4

​  

×π×(  

2

a

​  

)  

3

 

​  

 

=  

3

4

​  

×π×  

2

1

​  

 

=  

6

π

​

Answer 2

Answer:

82 is the correct answer

Explanation: