Question

Calculate the number of Pt atoms in the cube and find the radius in picometers of a Pt atom. Be sure your answer has the correct number of significant digits. Full questions are in pictures...Thank you!

Answer 1

V cube = 2.2³ = 10.648 cm³

V Pt atoms = 0.75(75%) x 10.648 = 7.986 cm³

Part 1

mass of a single Pt atom = 3.24 x 10⁻²² g

mass Pt atoms = ρ x V = 21.45 g/cm³ x 7.986 cm³ = 171.3 g

the number of Pt atoms = 171.3 : 3.24 x 10⁻²² = 5.287 x 10²³

Part 2

4/3πr³=7.986 cm³

r = 1.24 cm = 1.24 x 10¹⁰ pm