## How do you find the FCC planar density?

Find the area of the plane. As an example, the area of a (1 1 0) plane of an FCC crystal is 8_sqrt(2)_R^2 where “R” is the radius of an atom within the plane. Calculate planar density with the formula: PD = Number of atoms centered on a given plane / Area of the plane.

## What is the atomic density of 111 plane in FCC?

For (111): From the sketch, we can determine that the area of the (111) plane is (v2a./2) (va/V2) = 0.866a.. There are (3) (1/2) + (3) (1/6) = 2 atoms in this area. planar density = 2 points 0.866(3.5167 x 10-8 cm)?

0.74

## What is the packing fraction of BCC unit cell?

They occupy the maximum possible space which is about 74% of the available volume. Hence they are called closest packing. In addition to the above two types of arrangements a third type of arrangement found in metals is body centred cubic (bcc) in which space occupied is about 68%.

68%

## What is packing efficiency of HCP?

The packing efficiency of both types of close packed structure is 74%, i.e. 74% of the space in hcp and ccp is filled. The hcp and ccp structure are equally efficient; in terms of packing. The packing efficiency of simple cubic lattice is 52.4%. And the packing efficiency of body centered cubic lattice (bcc) is 68%.

## What is true about NaCl?

It is a salt because it decreases the concentration of metallic ions. It is an acid because it is formed by the reaction of a salt and an acid. It is a salt because it is formed by the reaction of an acid and a base. It is an acid because it increases the concentration of nonmetallic ions.

## What is the coordination number of Cs+ and Cl ions in the CSCL structure?

The coordination number is 8 : 8 in Cs+ and Clâˆ’.

6

## Why does CsCl have a different crystal packing arrangement than NaCl?

CsCl and NaCl do not adopt identical crystal packing arrangements because the Cs + ion is considerably larger than the Na + ion. In a cesium chloride crystal, the cesium ion (orange) occupies the center, while the chloride ions (green) occupy each corner of the cube. The coordination number for both ions is 8.

## Why are the packing arrangements for Na+ and Cs+ different?

Why are the packing arrangements for Na+ and Cs+ different? The cesium ion is much larger than the sodium ion.