Free Radical

{
  "id": "MLC-T-ENV-011671",
  "term": "Free Radical",
  "field": "Environment",
  "definition": "1. A chemical whose molecular or ionic structure includes an unpaired (\"free\") electron, usually conferring high reactivity; in biological systems, most free radicals contain oxygen.\n\n2. A highly reactive molecule with an unsatisfied electron valence pair. Free radicals are produced in both normal and pathological processes. They are proven or suspected agents of tissue damage in a wide variety of circumstances including radiation, damage from environment chemicals, and aging. Natural and pharmacological prevention of free radical damage is being actively investigated.\n\n3. Atomic or molecular species with unpaired electrons or an otherwise open shell configuration, usually very reactive. Specific to atmospheric chemistry, free radicals are: short-lived, highly reactive, intermediate species produced by dissociation of the source molecules by solar ultraviolet radiation or by reactions with other stratospheric constituents. Free radicals are the key to intermediate species in many important stratospheric chain reactions in which an ozone molecule is destroyed and the radical is regenerated. See ozone\n\n4. Radical molecule contains at least one unpaired electron. With few exceptions, these unpaired electrons make free radicals highly chemically reactive towards other substances or themselves.\n\n5. Atom or group of atoms with at least one unpaired electron, making the species unstable and highly reactive.",
  "references": [
    "NIH Genetics Home Reference Glossary",
    "NASA Earth Observatory Glossary",
    "Adapted from Community Multiscale Air Quality (CMAQ) Glossary",
    "Basic Concepts in Environmental Sciences"
  ],
  "url": "https://mlchart.com/terminology/environment/free-radical/"
}