DNA DNA Deoxyribonucleic acid (; DNA) is a molecule composed of two chains that coil around each other to form a double helix carrying the genetic instructions used in the growth, development, functioning and reproduction of all known living organisms and many viruses. DNA and ribonucleic acid (RNA) are nucleic acids; alongside proteins, lipids and complex carbohydrates (polysaccharides), nucleic acids are one of the four major types of macromolecules that are essential for all known forms of life. The two DNA strands are also known as polynucleotides as they are composed of simpler monomeric units called nucleotides. Each nucleotide is composed
Hexafluorosilicic acid Hexafluorosilicic acid Hexafluorosilicic acid is an inorganic compound with the chemical formula (also written as ). It is a colorless liquid rarely encountered undiluted. Hexafluorosilicic acid has a distinctive sour taste and pungent smell. It is produced naturally on a large scale in volcanoes. It is manufactured as a precursor to aluminum trifluoride and synthetic cryolite. It is commonly used as a source of fluoride for water fluoridation. Salts derived from hexafluorosilicic acid are called hexafluorosilicates. In aqueous solution, the hydronium cation (HO) is traditionally equated with a solvated proton, and as such, the formula for this compound is often