Molecules

Definition

Molecules are defined chemical compounds in which at least two, but usually more, atoms are covalently bonded together. Typical atoms in molecules are nonmetals such as carbon (C), hydrogen (H), oxygen (O), nitrogen (N), sulfur (S), phosphorus (P), and halogens (fluorine (F), chlorine (Cl), bromine (I), iodine (I)). Organic compounds contain carbon atoms. The various atoms differ in their tendency to form bonds.

Properties

In the strict sense, molecules include only uncharged compounds. However, molecules are often ionized, that is, positively or negatively charged. Unlike ionic compounds or salts, the atoms in molecules share their valence electrons and do not give them to the bonding partner. Salts such as sodium chloride occur in the form of crystals. In sodium chloride, each anion and each cation in the ionic lattice is surrounded by 6 counterions. The actual compound “NaCl” does not occur in this way, it merely indicates the ratio of the ions. Molecules, unlike salts, often have lower melting and boiling points and burn or decompose at lower temperatures.

Examples

  • Most active pharmaceutical ingredients are molecules.
  • Water (H2O)
  • Hydrogen is present as a diatom (H2, H-H) the smallest and lightest molecule.
  • Oxygen (O2)
  • Alcohol (ethanol)
  • Sugar (sucrose)
  • Caffeine