I think it is Bohr's model of the hydrogen atom led to an accurate calculation of the wavelengths of light emitted by an excited hydrogen atom. Niels Bohr introduced the atomic Hydrogen model in 1913. He described it as a positively charged nucleus, comprised of protons and neutrons, surrounded by a negatively charged electron cloud.
Niels Bohr was a physicist who contributed to the understanding of atoms, through is model that he idealised using Hydrogen as an example, because it's the simplest element existing.
