00:01
So the concept involved here is finding the density for the cubic unit cell.
00:09
Now, first of all, we have to calculate the edge length for the cubic unit cell we have been given.
00:18
So it is a bcc type of cell that is body -centered cubic unit cell.
00:25
So for bcc, that is body -centered cubic -unit cell.
00:33
The relation between edge length and radius.
00:38
So edge length is represented by a.
00:43
So this will be equal to 4 divided by under root 3 multiplied by r.
00:52
So r is the atomic radius here.
00:55
So putting the values, a is equal to 4 divided by the under root 3 can be solved and it will be be 1 .73 multiplying the atomic radius is given to us that is 125 picometer.
01:21
So solving this 289 .01.
01:31
So this is in picometer.
01:35
So now here is very important thing to be noted that this is in picometer and we have to calculate the density in gram per centimeter cube.
01:45
So you have to convert the units.
01:48
So for that edge length a is equal to 289 .01 multiplying 10 raise to power minus 10 centimeter...