A hypothetical AX type of ceramic material is known to have a density of 3.15 g/cm3 and a unit cell of cubic symmetry with a cell edge length of 0.41 nm. The atomic weights of the A and X elements are 90.5 and 37.3 g/mol, respectively. On the basis of this information, which one of the following crystal structures is possible for this material? a. Sodium chloride
b. Cesium chloride
c. Zinc blende

b.

Explanation:

From the given information:

where;

a = 0.41 nm =

M = 90.5 + 37.3 = 127.8 g/mol

p = 3.15 g/cm³

∴

Z = 1

Thus, the ceramic material has a simple cubic crystal system and the crystal structure is possible to be Cesium chloride.

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.