Q. Evolution of the Modern Atomic Model?

Ans: The atomic models of Dalton, Thomson, Rutherford, and Bohr eventually evolved into the current-day Quantum Mechanical model of the atom.

Bohr's atomic model is important because it laid the foundation for our understanding of atomic structure.

Bohr's model proposed that electrons orbit the nucleus in fixed circular paths. Although Bohr's atomic model was successful for the hydrogen atom, it was not successful for heavier atoms that had more than one electron. For example, when Bohr's theory was used to explain the arrangement of the electrons in the helium atom, there was a 5% error, compared to the 0.1% error when his theory was applied to the hydrogen atom. Although scientists tried, they could not adapt Bohr's theory to work with atoms heavier than hydrogen. Scientists concluded that electrons did not orbit the nucleus in the well-defined paths that Bohr predicted.