Cubic Unit Cell Structures

The video explores the arrangement of particles in crystalline solids, focusing on unit cells and cubic crystal systems. It details the simple, body-centered, and face-centered cubic unit cells, explaining their structures and coordination numbers. The video also discusses stacking methods and their efficiency, highlighting the rare occurrence of simple cubic structures in nature. Finally, it examines the structures of ionic compounds like sodium chloride and zinc sulfide, illustrating how ions interpenetrate in these crystals.

What is the smallest portion of a crystal structure that defines its overall structure?

• Atom

• Ion

• Unit cell

• Molecule

In a simple cubic unit cell, how many nearest neighbors does each particle have?

• 4

• 6

• 8

• 12

Which of the following is true about the body-centered cubic unit cell?

• It has particles only in the center.

• It has particles only at the corners.

• It has a particle at each corner and one in the center.

• It has particles at each face but none in the center.

How many particles are there in a body-centered cubic unit cell?

• 2

• 4

• 1

• 3

In a face-centered cubic unit cell, how many nearest neighbors does each particle have?

• 12

• 8

• 6

• 10

Which stacking arrangement is based on the face-centered cubic unit cell?

• Cubic closest packing

• Body-centered cubic packing

• Simple cubic packing

• Hexagonal closest packing

What percentage of volume is occupied by spheres in a simple cubic unit cell?

• 52%

• 74%

• 68%

• 80%

Which type of cubic unit cell is rarely seen in nature due to its inefficiency?

• Hexagonal closest packing

• Face-centered cubic

• Body-centered cubic

• Simple cubic

What structure does sodium chloride adopt?

• Hexagonal structure

• Diamond structure

• Rock salt structure

• Zinc blend structure

In the zinc blend structure, how is each ion surrounded?

• By 4 ions in a tetrahedral arrangement

• By 6 ions in an octahedral arrangement

• By 8 ions in a cubic arrangement

• By 12 ions in a dodecahedral arrangement