In a $ccp$ arrangement,the percentage of space occupied by spheres is ........ (in $\%$).

In a face-centered cubic $(FCC)$ close-packed structure,the third layer covers the ..... voids created between the first and second layers.

Write a short note on: Formula of a compound and number of voids filled.

In a cubic close packed structure,the fractional contributions of an atom at the corner and at the face in the unit cell are,respectively:

In a crystalline solid,anion $B$ are arranged in $ccp$ lattice and cation $A$ occupy $50\%$ of the octahedral voids and $50\%$ of tetrahedral voids. What will be the formula of the crystalline solid?

In a solid compound,the atoms of $A$ form a face-centered cubic $(fcc)$ lattice,while atoms of $B$ occupy all octahedral voids and half of the tetrahedral voids. The molecular formula of the solid will be ........