Flat Framework 2D Hexagonal and Square Packing

The video tutorial explains two types of close packing in two dimensions: square close packing and hexagonal close packing. In square close packing, spheres are arranged in rows where each sphere is in contact with four neighbors, forming a square pattern. This arrangement is referred to as a a a A type, with a coordination number of 4. In hexagonal close packing, spheres are arranged in an ABAB pattern, where each sphere is in contact with six neighbors, forming a hexagonal pattern. The coordination number for this arrangement is 6. The video highlights the differences between these packing types and their respective coordination numbers.

In square close packing, how many nearest neighbors does each sphere have?

• 3

• 4

• 2

• 6

What shape is formed when the centers of four neighboring spheres are joined in square close packing?

• Square

• Hexagon

• Pentagon

• Triangle

In hexagonal close packing, what is the coordination number of each sphere?

• 2

• 4

• 8

• 6

How are the rows arranged in hexagonal close packing?

• In a straight line

• In a zigzag pattern

• In a circular pattern

• In a staggered manner

What type of arrangement is formed by alternating layers in hexagonal close packing?

• ABBA

• ABAB

• AAAA

• AABB