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Problem: The unit cells for lithium oxide and silver iodide are shown. Identify the structure of each of the two unit cells shown below as the rock salt structure, zinc blende structure, fluorite structure, antifluorite structure, or none of these.

FREE Expert Solution

In this problem, we are asked to identify the shown structure of Lithium oxide and Silver iodide as the structure of rock salt, zinc blende, fluorite, antifluorite, or none of the given choices.


Recall that unit cells are the smallest divisible unit of a crystal that, when repeated in three dimensions, reproduces the entire crystal lattice. 


We are given the figure of the structure of the unit cell of the compound:

The figure shows 2 unit cells: one for lithium oxide and the other for silver iodide. Lithium oxide unit cell has oxygen atoms at the corners of the cube and also in the center of each face of the cube. There are 8 lithium atoms as well: each of them is connected to 1 oxygen atom in the corner and 3 oxygen atoms in the faces. Silver iodide unit cell has iodine atoms at the corners of the cube and also in the center of each face of the cube. There are also 4 silver atoms as well: each of them is connected to 1 oxygen atom in the corner and 3 oxygen atoms in the faces. 2 of silver atoms are located in the upper part of the unit cell, and 2 other atoms are in the lower part of it.


We can see that that structure is cubic, with 1 atom in each corner of the cube

We can also see that there is 1 atom in every cube face. Thus, the two unit cells shown is a face-centered cubic unit cell.


To solve this problem:

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Problem Details
The unit cells for lithium oxide and silver iodide are shown. Identify the structure of each of the two unit cells shown below as the rock salt structure, zinc blende structure, fluorite structure, antifluorite structure, or none of these.

The figure shows 2 unit cells: one for lithium oxide and the other for silver iodide. Lithium oxide unit cell has oxygen atoms at the corners of the cube and also in the center of each face of the cube. There are 8 lithium atoms as well: each of them is connected to 1 oxygen atom in the corner and 3 oxygen atoms in the faces. Silver iodide unit cell has iodine atoms at the corners of the cube and also in the center of each face of the cube. There are also 4 silver atoms as well: each of them is connected to 1 oxygen atom in the corner and 3 oxygen atoms in the faces. 2 of silver atoms are located in the upper part of the unit cell, and 2 other atoms are in the lower part of it.

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Unit Cell concept. You can view video lessons to learn Unit Cell. Or if you need more Unit Cell practice, you can also practice Unit Cell practice problems.

What professor is this problem relevant for?

Based on our data, we think this problem is relevant for Professor Kuebler's class at UCF.