Question

In a cubic close packing containing 100 layers of atoms which of the given layer are expected to be identical. 1)layer 5 and layer 19. 2)layer 11 and layer 98. 3)layer 4 and layer 38. 4)layer 17 and layer 90

Answer 1

Answer:

The identical layers are that of 11 and 98.

Explanation:

In cubic close packing arrangements , the atoms follow the abc  arrangement , in which the first and the fourth layer after it are identical

the layers identical are

1st , 4th, 7th , 10th... be category 1

2nd, 5th, 8th .. be category 2

3rd, 6th , 9th... be category 3

layer 5 comes in category 2 while that of 19 comes in category 1 , therefore these two layers are not identical

layer 11 comes in category 2 and that of 98 is also included in category 2

Therefore the  layers 11 and 98 are identical