Which one of the following statements about solid cu (face-centered cubic unit cell) is incorrect?
a) it will conduct electricity.
b) there are two atoms per unit cell.
c) the number of atoms surrounding each cu atom is 12.
d) the solid has a cubic closest-packed structure.
e) the length of a face diagonal is four times the cu radius

B) There are two atoms per unit cell.

Explanation:

In the face-centered cubic cell, there are spheres (which represent molecules or atoms) at the center of each of the six faces of the cube, in addition to eight corner spheres.

Because every unit cell in a crystalline solid is adjacent to other unit cells, most  of a cell’s atoms are shared by neighboring cells.

A face-centered cubic cell contains the equivalent of four complete spheres or atoms—three from  the six face-centered atoms and one from the eight shared corner spheres.

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

16

explanation:

the marks go by 4s