3D Hexagonal Closed Packing Layered Perfection

The video tutorial explains the concept of three-dimensional closed packing using layers of spheres. It begins with the formation of the first layer, known as layer A, and introduces the concept of voids. The second layer, layer B, is placed over the first, creating tetrahedral and octahedral voids. The third layer, also called layer A, aligns with the first, forming an ABAB pattern known as hexagonal closed packing (HCP) with a coordination number of 12. The video also covers the ABCABC arrangement, leading to cubic closed packing or face-centered cubic structure.

What is the name given to the first layer in three-dimensional closed packing?

• Layer C

• Layer A

• Layer B

• Layer D

In the first layer, what are the voids pointing upwards called?

• A voids

• C voids

• D voids

• B voids

What type of void is formed when the second layer is placed over the first layer?

• Spherical void

• Cubic void

• Tetrahedral void

• Hexagonal void

How many spheres are in contact with a space in an octahedral void?

• Seven

• Six

• Four

• Five

What is the coordination number in a hexagonal closed packing (HCP) arrangement?

• 8

• 10

• 12

• 14

What is the arrangement called when the third layer aligns with the first layer?

• ABAB arrangement

• ABCABC arrangement

• ABCA arrangement

• AABB arrangement

What is another name for the ABCABC arrangement?

• Hexagonal closed packing

• Simple cubic

• Face-centered cubic

• Body-centered cubic