Simple Cubic Unit Cell

the body center cubic unit cell is composed of a cube with an atom at each corner and one atom in the center. So we would say that when it comes to a body centered cubic unit some we have a total of two atoms involved. And remember one of those atoms is found in the center of our structure. Now remember each one of these red spheres. It is shared by other unit cells around. So each one of these only accounts for 1/8 of an atom. And if you took them all into consideration 1/8 times eight corners gives us one atom here. And then we have this one atom in the very center. So that's how we come up with two total atoms for body center, cubic unit self. Now we can say here that when it comes to a simple cubic unit cell we knew that the M. D. A. Or an edge length was equal to two R. That's because the atoms touched one another. But when it comes to a body centered cubic in itself there's a small little gap here as a result of this small gap. That means our edge link now changes our edge link now is equal to four times your radius divided by the square root of three. So a here equals four are divided by square root of three. Now, as we become more and more complex are packing efficiency will increase here for body centre cubic unit cell it becomes now 68%. And as we become more complex, our coordination number also increases here for body centered cubic unit cell, it now becomes the value of eight. So when dealing with body centered cubic unit cell, remember these key ideas and key values for any one of them.

calculate the volume in centimeters cube of a simple cubic unit cell. If it's composed of atoms with a radius of 2.5 banks trumps. All right. So just remember that volume equals your edge length cube. And this is true for any cube. And we're going to say here that are edge length for a simple cubic unit cell is edge length A is equal to two times my radius Because our volume needs to be in cm. We have to convert our Angstrom also in two cm. So we have 25 angstrom. Remember the conversion factor is that one? Angstrom is equal to 10 to the negative 10 m m goals here in cm up here, one senti is 10 to the -2. So this comes out to be 2.5 times 10 to the negative eight cm. So that's my radius and centimeters. So now multiply it by two. So this equals 50 times 10 to the negative eight cm. And then all we have to do here is cube this number and we'll have our volume in centimeters cubed. So when I cube this, it's going to give me back as an answer. 1.3 times 10 to the negative cm cubed. So this would be our final answer.