Number of Atoms in a Unit Cell

ABCABC arrangement packing efficiency in face centred cubic lattice is $100\%$.

Explain how much portion of an atom located at:

Body centre of a cubic unit cell is part of its neighbouring unit cell.

Explain how much portion of an atom located at: 

Corner?  

How will you distinguish between the following pairs of terms? 

Face centred and body centred cubic cell. 

How many lattice points are in unit cells of following lattice? 

Body centred. 

How many lattice points are in unit cells of following lattice? 

Face centred tetrahedral

An ionic compound ${\mathrm{A}}_{\mathrm{x}}{\mathrm{B}}_{\mathrm{y}}$ occurs in fcc type crystal structure with $\mathrm{B}$ ion at the centre of each face and $\mathrm{A}$ ion occupying corners of the cube. Give the formula ${\mathrm{A}}_{\mathrm{x}}{\mathrm{B}}_{\mathrm{y}}$.

A compound formed by elements $\mathrm{A}$ and $\mathrm{B}$ crystallizes in the cubic where $\mathrm{A}$ atoms are at the corners of the cube and $\mathrm{B}$ are at the face centres. The formula of compound is :

Give the number of lattice points in one unit cell of the crystal structures.

Face centered tetragonal

Give the number of lattice points in one unit cell of the crystal structures.

Body centered cubic

Give the number of lattice points in one unit cell of the crystal structures.

Face centered cubic

Give the number of lattice points in one unit cell of the crystal structures.

Simple cubic

An atom at the corner of a simple cubic cell is shared by 

A crystal is formed by two elements $\mathrm{X}$ and $\mathrm{Y}$ in cubic structure. $\mathrm{X}$ atoms are at the corners of a cube while $\mathrm{Y}$ atoms are at the face centre. The formula of the compound will be

The number of unit cells present in $\text{39}\text{g}$ of potassium if it crystallizes as body centred cube is ($\text{N}\text{=}$ Avogadro number, At. Wt. of potassium = $\text{39}\text{g/mol}$ )

An ionic compound has a unit cell consisting of $\mathrm{A}$ ions at the corners of a cube $\mathrm{B}$ ions on the centres of the faces of the cube but one axis of faces are missing. The empirical formula for this compound would be

A compound formed by elements $\mathrm{A}$ and $\mathrm{B}$ crystallize in a cubic structure, where atoms of $\mathrm{A}$ are at the corners of a cube and atoms of $\mathrm{B}$ are at the face centre of a cube. What is the formula of the compound formed?

A compound is formed by elements $\mathrm{A}$ and $\mathrm{B}$. This crystallizes in the cubic structure where the $\mathrm{A}$ atoms are at the corners of the cube and $\mathrm{B}$ atoms are at the body centres. The simplest formula of the compound is

A solid compound contains $\mathrm{X},\mathrm{ }\mathrm{Y}$ and $\mathrm{Z}$ atoms in a cubic lattice with $\mathrm{X}$ atoms occupying the corners, $\mathrm{Y}$ atoms in the body centred positions and $\mathrm{Z}$ atoms at the centre of the faces of the unit cell. What is the empirical formula of the compound ?

The packing fraction of the element that crystallizes in simple cubic arrangement is -