Compounds of copper(II) are generally colored, but compounds of copper(I) are usually colorless. Use crystal field theory to explain why this is true.

See explanation

Explanation:

The crystal field theory assumes the interaction between the central metal ion and ligands to be purely electrostatic.

The five d orbitals remain degenerate until they are surrounded by ligands which split the degeneracy of the d orbitals depending on the crystal fields formed to give either square planar, octahedral, tetrahedral or other kinds of crystal fields.

The electronic configuration of Cu II ion is 1s2 2s2 2p6 3s2 3p6 3d9. Its colour arises from an incomplete d orbital which makes d - d electron transition possible.

On the other hand, the electron configuration of copper I is  1s2 2s2 2p6 3s2 3p6 3d10. We can see that the d orbital is completely filled. Hence copper I ion has no color due to its completely filled d- orbitals

the grams   of   barium that   are in   2.3 x 10^23   atoms of barium   is   52.4 g (answer c)

    calculation

mass = moles   of ba   x molar   mass of ba

  molar mass of ba from periodic table=   137.3 g/mol

  use the   avogadro's law   constant   to   calculate the moles of barium

  that   is     1 mole =   6.02   x 10^23 atoms

                    ? moles = 2.3 x 10^23   atoms

by cross   multiplication

=(1 mole   x 2.3x 10^23 atoms)   / 6.02   x10^23 atoms)=   0.382   moles

mass   is therefore = 137.3   g/mol x 0.382 mol = 52.4 ( answer c)

explanation: