Science / Chemistry / Halogen: An element of group VIIA (a. K. A. Group 18). The name means 'salt former'; halogens react with metals to form binary ionic compounds. Fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At) are known at this time.


Entertainment / Photography / Rehalogenization: Process by which black metallic silver is converted back to silver halides. It is used in bleaching for toners and intensification. MORE


Entertainment / Photography / Halogens: Collective term for the elements chlorine, bromine and iodine, which are combined with silver to produce the light sensitive crystals used as the basis for photographic emulsions. MORE

Tungsten Halogen Lamp

Entertainment / Photography / Tungsten Halogen Lamp: Improved version of the normal tungsten lamp. It is much smaller and more consistent in color temperature as the glass envelope used is non-blackening. MORE

Sodium (Na)

Science / Periodic Table of Elements / Sodium (Na): Atomic number: 11, Atomic mass: 22.98977 g.mol -1, Electronegativity: 0.9, Density: 0.97 g.cm -3 at 20 °C, Melting point: 97.5 °C, Boiling point: 883 °C, Vanderwaals radius: 0.196 nm, Ionic radius: MORE

Cesium (Cs)

Science / Periodic Table of Elements / Cesium (Cs): Atomic number: 55, Atomic mass: 132.9054 g.mol -1, Electronegativity: 0.7, Density: 1.9 g.cm-3 at 20°C, Melting point: 28.4 °C, Boiling point: 669 °C, Vanderwaals radius: 0.267 nm, Ionic radius: 0. MORE

Silicon (Si)

Science / Periodic Table of Elements / Silicon (Si): Atomic number: 14, Atomic mass: 28.0855 g.mol -1, Electronegativity: 1.8, Density: 2.33 g.cm -3 at 20 °C, Melting point: 1410 °C, Boiling point: 3265 °C, Vanderwaals radius: 0.132 nm, Ionic radius: MORE