H-alpha (HÎ±) is a specific deep-red visible spectral line in the Balmer series created by hydrogen with a wavelength of 656.28 nm, which occurs when a hydrogen electron falls from its third to second lowest energy level.herefore, the H-alpha line occurs where hydrogen is being ionized. The H-alpha line saturates (self-absorbs) relatively easily because hydrogen is the primary component of nebulae, so while it can indicate the shape and extent of the cloud, it cannot be used to accurately determine the cloud's mass.
Seven Years War (1756-1763) The Seven Years War was the first global conflict. It had two main fronts. The first, in Europe, was the hostility between Prussia and Austria, still simmering after the War of the Austrian Succession , which expanded through alliances to include all of Europe.
When Did the Vietnam War Start and End. 04 Mar, 2011 when did 0. The Vietnam War was a sad and unnecessary time in the history of a number of countries including South Vietnam, the United States of America, Australia, New Zealand, South Korea, Philippines, Thailand, and Laos.he Vietnam War ended with the fall of Saigon on April 30th 1975. The Viet Cong gained control of this city which had been the South Vietnamese Political base. Thousands of U.S. diplomatic, military, and civilian personnel were evacuated via helicopter.