GEOLOGY

Detailed explanation-1: -The simple cubic unit cell is delineated by eight atoms, which mark the actual cube. These are corner atoms, so each one only contributes one eighth of an atom to the unit cell, thus giving us only one net atom.

Detailed explanation-2: -A particle at the corner of a unit cell is shared by eight-unit cells. So, each particle contributes 18 part to the unit cell.

Detailed explanation-3: -An atom on an edge is shared by four unit cells, and an atom on a corner is shared by eight unit cells.

Detailed explanation-4: -In a face-centered cubic lattice, a unit cell is shared equally by 6 unit cells.

Detailed explanation-5: -In the primitive cubic unit cell, the atoms are present only at the corners. Every atom at the corner is shared among 8 adjacent unit cells. There are 4 unit cells in the same layer and 4 in the upper (or lower) layer. Therefore, a particular unit cell has only 1/8th of an atom.