Halogen Blue

Halogen

The halogens are a group in the periodic table consisting of six chemically related elements, fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and the radioactive elements astatine (At) and tennessine (Ts), though some authors would exclude tennessine as its chemistry is unknown and is theoretically expected to be more like that of gallium. In the modern IUPAC nomenclature, this group is known as group 17.

Blue

Blue is one of the three primary colours in the RGB (additive) colour model, as well as in the RYB colour model. It lies between violet and cyan on the spectrum of visible light. The term blue generally describes colours perceived by humans observing light with a dominant wavelength between approximately 450 and 495 nanometres. The clear daytime sky and the deep sea appear blue because of an optical effect known as Rayleigh scattering. An optical effect called the Tyndall effect explains blue eyes. Distant objects appear more blue because of another optical effect called aerial perspective.

halogen

Noun

1. Any element of group 17, i.e. fluorine, chlorine, bromine, iodine, astatine and tennessine.
2. A light fixture in which the filament is surrounded by an atmosphere of a halogen gas.

blue

Adjective

1. Of a blue hue.
2. Depressed, melancholic, sad.

Noun

1. The colour of the clear sky or the deep sea; the colour midway between green and violet in the visible spectrum and one of the primary additive colours.
2. Anything coloured blue, especially to distinguish it from similar objects differing only in colour.