Density of Crystal Lattice Formula

What is density?

Density formula for crystal lattice, liquid, and gases is the measurement of mass per unit volume at a given temperature and pressure. It is expressed by the symbol ρ or D. Mathematically density is expressed by the formula, ρ = m/V, where m = mass of the substance and V = volume.

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Density formula for cubic crystal lattice

The density based on the crystal lattice can be calculated from the mass and volume of the unit cell. In this topic, we can discuss the density of cubic crystal lattices. If n is the number of molecules per unit cubic cell of edge length a, then the mass of the unit cell = nM/N, where N = Avogadro number. The volume of the cell = a3. Therefore, the density of cubic crystal lattice = mass/volume = nM/a3N.

The values of n for three cubic cells are,

• For primitive cells, n =1.
• For Body-centered cells, n = 2.
• For face-centered cubic cells, n = 4.