I thinking the limitation is that a shifting electron will always move from a more excited states to a less excited state. Electrons could not circle the nucleus because they would lose energy by emitting electromagnetic radiation and spiral into the nucleus. In addition Bohr was not able to explain electrons orbits of large atom w/many electrons.
E=hc/λ =6.626×10^-34×3 ×10^8 / 3×10^7 × 10^-9 = 6.626×10 ^-24J.
Thus, it was found that the intestinal microbiota has approximately 100 trillion bacterial cells - about ten times more than the total number of cells in the human body.
Answer:
I believe this is called the 'molar mass'