A metal crystallizes in the face‑centered cubic (FCC) lattice. The density of the metal is 12020 kg/m3, and the length of a unit cell edge, , is 389.08 pm. Calculate the mass of one metal atom in grams.

  1.7700×10^-22 g

Explanation:

A face-centered-cubic cell contains 4 atoms, so the volume per atom is ...

  (389.80×10^-12 m)³/(4 atoms) ≈ 1.4725×10^-29 m³

Then the mass of 1 atom is ...

  (12020 kg/m³)(1.4725×10^-29 m³) ≈ 1.76995×10^-25 kg

  ≈ 1.7700×10^-22 g

Additional comment

That is the approximate mass of a Palladium atom.

the increase of protons   hope this