- Star Tales - Canis Major (ianridpath.com)
Four dogs are to be found among the constellations: Canis Major, Canis Minor, and the two hunting dogs of Canes Venatici, but Canis Major is undoubtedly the top dog. Indeed, Ptolemy in the Almagest called it simply Κύων (Kyon), the Dog. Canis Major is dominated by Sirius, popularly termed the Dog Star, the most brilliant star in the entire night sky; almost certainly the constellation originated with this star alone.
- Ionic compound (Wikipedia)
In chemistry, an ionic compound is a chemical compound composed of ions held together by electrostatic forces termed ionic bonding. The compound is neutral overall, but consists of positively charged ions called cations and negatively charged ions called anions. These can be simple ions such as the sodium (Na+) and chloride (Cl−) in sodium chloride, or polyatomic species such as the ammonium and carbonate ions in ammonium carbonate. Individual ions within an ionic compound usually have multiple nearest neighbours, so are not considered to be part of molecules, but instead part of a continuous three-dimensional network. Ionic compounds usually form crystalline structures when solid.