Acube of copper metal has a density of 8.96 g/cm3. the cube has a mass of 29.54 g. the atomic radius of a copper atom is 1.28 angstroms. how many atoms is the cube of copper metal?

The answer to your question is:  3.745 x 10 ²³ atoms

Explanation:

Data

density = 8.96 g/cm³

mass = 29.54 g

atomic radius = 1.28 A° 1.28 x 10⁻¹⁰ m

Volume of a cube

                              density = mass / volume

                              volume = mass / density

                              volume = 29.54 / 8.96

                              volume = 3.29 cm³

Volume of a copper atom

                              volume = (4/3) πr³

                              volume = (4/3) π (1.28 x 10 ⁻⁸)³

                                           = 8.784 x 10 ⁻²⁴ cm³

Number of atoms = 3.29 cm³ / 8.784 x 10 ⁻²⁴ cm³

                             = 3.745 x 10 ²³ atoms

the reaction mixture contains some ammonia, plus a lot of unreacted nitrogen and hydrogen. the mixture is cooled and compressed, causing the ammonia gas to condense into a liquid. the liquefied ammonia is separated and removed. the unreacted nitrogen and hydrogen are then recycled back into the reactor .

i believe the answer is a.