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 the absolute smallest of all elements, so small that four billion, laid end to end, could fit on the head of one pin! At room temperature hydrogen is a clear gas. Hydrogen gas (H 2) is a molecule made of two hydrogen atoms bonded together.