Lithium β is a solid phase of lithium still unknown to science. The only difference between it and ordinary lithium is that Lithium β forms a crystal with an fcc unit cell and a lattice constant =a0.430 nm. Calculate the density of Lithium β

The density of Lithium β is 0.5798 g/cm³

Explanation:

For a face centered cubic (FCC) structure, there are total number of 4 atoms in the unit cell.

we need to calculate the mass of these atoms because density is mass per unit volume.

Atomic mass of Lithium is 6.94 g/mol

Then we calculate the mass of four atoms;

⇒next, we estimate the volume of the unit cell in cubic centimeter

given the edge length or lattice constant a = 0.43nm

a = 0.43nm = 0.43 X 10⁻⁹ m = 0.43 X 10⁻⁹ X 10² cm = 4.3 X 10⁻⁸cm

Volume of the unit cell = a³ = (4.3 X 10⁻⁸cm)³ = 7.9507 X 10⁻²³ cm³

⇒Finally, we calculate the density of Lithium β

Density = mass/volume

Density = (4.6097 X 10⁻²³ g)/(7.9507 X 10⁻²³ cm³)

Density = 0.5798 g/cm³

hope this

explanation:

covalent bonds

consist of pairs of electrons shared by two atoms, and bind the atoms to fixed orientation and requre high energies to break them

ionic bonds

when two atoms differ considerably in their electronegativity, then one of the atoms will lose its electron to the other atom. this results in a positively charged ion(cation) and a negatively charged ion (anion)