In physics and astronomy, H-alpha, also written Hα, is a particular emission line created by hydrogen. The willingness to question previously held truths and search for new answers resulted in a period of major scientific advancements, now known as the Scientific Revolution. ... Astronomy is one of the few sciences where amateurs can still play an active role, especially in the discovery and monitoring of transient phenomena. ... A spectral line is a dark or bright line in an otherwise uniform and continuous spectrum, resulting from an excess or deficiency of photons in a narrow frequency range, compared with the nearby frequencies. ... General Name, Symbol, Number Hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1 (IA), 1, s Density, Hardness 0. ...

According to the Bohr model of the atom, electrons exist in quantized energy levels surrounding the atom's nucleus. These energy levels are described by the angular momentum quantum number, n = 1, 2, 3, ... . Electrons may only exist in these states, and may only transition between these states. The set of transitions from n ≥ 3 to n = 2 are called the Balmer series and are named sequentially by Greek letter: n = 3 to n = 2 is called H-alpha, 4 to 2 is H-beta, 5 to 2 is H-gamma, etc. For the Lyman series the naming convention is 2 to 1 is Lyman-alpha, 3 to 1 is Lyman-beta, etc. The Bohr model of the atom In atomic physics, the Bohr model is a physical model that depicts the atom as a small positively charged nucleus surrounded by electrons in orbit at different levels, similar in structure to the solar system. ... Properties For alternative meanings see atom (disambiguation). ... Properties The electron (also called negatron, commonly represented as e−) is a subatomic particle. ... Generally, quantization is the state of being constrained to a set of discrete values, rather than varying continuously. ... The nucleus (atomic nucleus) is the center of an atom. ... The Principal quantum number (usually written n) is the first quantum number of an atomic orbital. ... The Balmer series is the series of transitions and resulting emission lines of the Hydrogen atom as an electron goes from n ≥ 3 to n = 2 (where n refers to the energy level of the electron). ... The Lyman series is the series of transitions and resulting emission lines of the hydrogen atom as an electron goes from n ≥ 2 to n = 1 (where n is the principal quantum number referring to the energy level of the electron). ...

H-alpha has a wavelength of 656.3 nm, is visible in the red part of the electromagnetic spectrum, and is the easiest way for astronomers to trace the Hydrogen content of gas clouds. The electromagnetic spectrum encompasses all possible wavelengths of electromagnetic radiation. ...

See also: Bohr model, Rydberg formula, Balmer series, Lyman series, Paschen series, Bracket series The Bohr model of the atom In atomic physics, the Bohr model is a physical model that depicts the atom as a small positively charged nucleus surrounded by electrons in orbit at different levels, similar in structure to the solar system. ... The Rydberg formula (Rydberg-Ritz formula) is used in atomic physics for determining the full spectrum of light emission from hydrogen, later extended to be useful with any element. ... The Balmer series is the series of transitions and resulting emission lines of the Hydrogen atom as an electron goes from n ≥ 3 to n = 2 (where n refers to the energy level of the electron). ... The Lyman series is the series of transitions and resulting emission lines of the hydrogen atom as an electron goes from n ≥ 2 to n = 1 (where n is the principal quantum number referring to the energy level of the electron). ... The Paschen series is the series of transitions and resulting emission lines of the hydrogen atom as an electron goes from n ≥ 4 to n = 3 (where n refers to the energy level of the electron). ...