Strontium (sr) has the fcc crystal structure, an atomic radius of 0.215 nm, and an atomic weight of 87.62 g/mol. what is its theoretical density?

Theoretical density =2.576g/cm³

Explanation:

Theoretical density p= (A×n)/Vc ×Av

A= molecular weight

n= effective number of atoms per unit cell

Vc=Volume of unit cell = a³

Av = Avogadro's constant = 6.02×10²³

Given that A= 87.2g/mol

n= 4 (For FCC crystal structure)

Vc= a³

Where a = 2R√2 and R is the atomic radius

R=0.215

a= 2 × 0.215×√2

a= 0.608nm = 0.608×10^-7 cm

Vc= (0.608×10^-7 cm)³

Vc=2.25×10^-22 cm³

P= (87.2 × 4)/

(2.25×10^-22) × (6.02×10²³)

P= 2.576g/cm³

Therefore the theoretical density of strontium is 2.576g/cm³

b..

is the correct one

explanation:

covalent bonds form as valence electrons are shared between two atoms. lewis structures and structural formulas are common ways of showing the covalent bonding in organic molecules. formal charge describes the changes in the number of valence electrons as an atom becomes bonded into a molecule.