A+E Networks. On this day in 1969, Americaâs first automatic teller machine (ATM) makes its public debut, dispensing cash to customers at Chemical Bank in Rockville Center, New York.
This modification of the energy levels of a hydrogen atom due to a combination of relativity and spin-orbit coupling is known as fine structure.
Hydrogen is a chemical element with chemical symbol H and atomic number 1. With an atomic weight of 7000100794000000000â 1.00794 u, hydrogen is the lightest element on the periodic table.Its monatomic form (H) is the most abundant chemical substance in the universe, constituting roughly 75% of all baryonic mass. Non-remnant stars are mainly composed of hydrogen in its plasma state.he universal emergence of atomic hydrogen first occurred during the recombination epoch. At standard temperature and pressure, hydrogen is a colorless, odorless, tasteless, non-toxic, nonmetallic, highly combustible diatomic gas with the molecular formula H 2.