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Nitrogen is a chemical element; it has symbol N and atomic number 7. Nitrogen is a nonmetal and the lightest member of group 15 of the periodic table, often called the pnictogens. It is a common element in the universe, estimated at seventh in total abundance in the Milky Way and the Solar System.
The Kármán line, at 100 km (62 mi) or 1.57% of Earth's radius, is often used as the border between the atmosphere and outer space. Atmospheric effects become noticeable during atmospheric reentry of spacecraft at an altitude of around 120 km (75 mi).
The excited nitrogen deexcites primarily by emission of a photon, with emission lines in ultraviolet, visible, and infrared band: N 2 * → N 2 + hν. The blue light observed is produced primarily by this process. [2] The spectrum is dominated by lines of single-ionized nitrogen, with presence of neutral nitrogen lines.
The spectrum also includes hydrogen lines and analysis shows the star is still 40% hydrogen at the surface. The helium and nitrogen in the atmosphere of such a young star are caused by strong convection due to the massive core and intense CNO cycle fusion, enhanced further by rotational mixing. The emission lines in the spectrum indicate strong ...
Absorptions bands in the Earth's atmosphere created by greenhouse gases and the resulting effects on transmitted radiation.. In spectroscopy, an absorption band is a range of wavelengths, frequencies or energies in the electromagnetic spectrum that are characteristic of a particular transition from initial to final state in a substance.
Strong spectral lines in the visible part of the electromagnetic spectrum often have a unique Fraunhofer line designation, such as K for a line at 393.366 nm emerging from singly-ionized calcium atom, Ca +, though some of the Fraunhofer "lines" are blends of multiple lines from several different species.
Liquid water and ice emit radiation at a higher rate than water vapour (see graph above). Water at the top of the troposphere, particularly in liquid and solid states, cools as it emits net photons to space. Neighboring gas molecules other than water (e.g. nitrogen) are cooled by passing their heat kinetically to the water.
Earth's atmosphere photographed from the International Space Station. The orange and green line of airglow is at roughly the altitude of the Kármán line. [1] The Kármán line (or von Kármán line / v ɒ n ˈ k ɑːr m ɑː n /) [2] is a conventional definition of the edge of space. It is not universally accepted.