Home
Class 11
CHEMISTRY
In hexagonal system of crystals, a frequ...

In hexagonal system of crystals, a frequently encountered arrangement of atoms is described as a hexagonal prism. Here, the top and bottom of the cell are regular hexagon and three atoms are sandwiched in between them. A space filling model of this structure, called hexagonal close packed (HCP), is constituted of a sphere on a flat surface surrounded in the same plane by six identical sphere as closely as possible. Three spheres are then placed over the first layer so that they touch other and represent the second layer. Each one of the three spheres touches three spheres of the bottom layer. Finally, the second layer is covered with a third layer that is identical to the bottom layer in relative position. Assume radius of every sphere to be same
The volume of this HCP unit cell is

A

`24sqrt2r^(3)`

B

`16sqrt2r^(3)`

C

`12sqrt2r^(3)`

D

`64/(3sqrt3)r^(3)`

Text Solution

Verified by Experts

The correct Answer is:
A
Height of unit cell =`sqrt(2/3)4r`
`"Base area" = 6timessqrt3/4(2r^(2))`
`"Volume" = (6sqrt3)/4(2r)^(2)*sqrt2/(3)4r=24sqrt2 r^(3)`
Promotional Banner

Topper's Solved these Questions

  • STATES OF MATTER (SOLID STATE CHEMISTRY)

    DINESH PUBLICATION|Exercise MATRIX MATCH TYPE MCQs|4 Videos

  • STATES OF MATTER (SOLID STATE CHEMISTRY)

    DINESH PUBLICATION|Exercise INTEGER TYPE QUESTIONS|1 Videos

  • STATES OF MATTER (SOLID STATE CHEMISTRY)

    DINESH PUBLICATION|Exercise SELECTED STRAIGHT OBJECTIVE TYPE MCQs|23 Videos

  • STATE OF MATTER (GASEOUS AND LIQUID STATE)

    DINESH PUBLICATION|Exercise Ulitmate Preparatory package|20 Videos

  • STATES OF MATTER : GASES AND LIQUIDS

    DINESH PUBLICATION|Exercise Statement Type Question|5 Videos