Metacognition is  cognition about cognition, thinking about thinking, or knowing about knowing. It comes from the root word  meta , meaning beyond. It can take many forms; it includes knowledge about when and how to use particular strategies for learning or for problem solving. There are generally two components of metacognition: knowledge about cognition, and regulation of cognition.
In chemistry, an ionic compound is a chemical compound in which ions are held together in a structure by electrostatic forces termed ionic bonds.The positively charged ions are called cations and the negatively charged ions are called anions.onic compounds without the acidic hydrogen ion (H +), or the basic ions hydroxide (OH â) or oxide (O 2â), are also known as salts and can be formed by acid-base reactions. Ionic compounds containing hydrogen ions are classified as acids and compounds containing hydroxide or oxide ions are classified as bases.
Quaternary ammonium compounds are cationic detergents, as well as disinfectants, and as such can be used to remove organic material. They are very effective in combination with phenols. Quaternary ammonium compounds are deactivated by anionic detergents (including common soaps).n di-quaternary ammonium compounds, this process can also result in the formation of fragment ions with higher mass as compared to their precursor ion.