Can anyone here do inorganic chemistry?

Bohr's model could only explain the spectra of which type of atoms? single atoms with one electron single atoms with more than one electron bonded atoms with one electron bonded atoms with more than one electron

Ahypothrticalax type of ceramic material is known to have a density of 2.10 g/cm3 and a unit cell of cubic symmetry with a cell edge length of 0.57 nm. the atomic weights of the a and x elements are 28.5and 30.0 g/mol, respectively. on the basis of this information, which of the following crystal structures is (are) possible for this material: sodium chloride, cesium chloride, or zinc blende

What was bohr’s contribution to the planetary model