Solving and balancing chemical equations

Compare and contrast the bohr model and the electron cloud models of the atom.

What are the first two quantum numbers for the electrons located in subshell 4d? what are the first three quantum numbers for the electrons located in subshell 2s? how many electrons can be held in a sublevel l = 3? how many electrons can be held in the energy level n = 4? how many electrons in an atom can share the quantum numbers n = 4 and l = 3?

What conclusion can you draw from this experiment about the components of the black ink?