Final answer:
Niels Bohr was a physicist who developed the Bohr model of the atom in 1913, contributing to the foundation of quantum mechanics and modern physics.
Step-by-step explanation:
Niels Bohr (1885-1962) was a pioneering physicist recognized for his groundbreaking work on the structure of atoms and the development of quantum mechanics. His Bohr model of the atom proposed in 1913, placed the atom's electrons in quantized orbits around the nucleus, leading to our understanding of atomic spectra, particularly for the hydrogen atom. Bohr's work fits into the timeline of history in the early 20th century, at a time when the foundations of modern physics were being established. He spent time at Rutherford's laboratory in 1912, where he built upon the planetary model of the atom. This was a period where many known atomic properties lacked physical explanations, and Bohr's theory helped bridge this gap.