Litmus paper

{
  "id": "MLC-T-ENV-015908",
  "term": "Litmus paper",
  "field": "Environment",
  "definition": "1. Paper coated with a chemical coloring obtained from lichens that turns red in acidic water and blue in basic water. It is used as an acid-base indicator.\n\n2. Paper that indicates how acidic or basic an object or liquid is. If the paper turns red when touched by the object or liquid, it is acidic. If the paper turns blue, the object or liquid is basic.",
  "subject": "Air",
  "references": [
    "Acid Rain Glossary",
    "Acid Rain Students Site: Glossary"
  ],
  "url": "https://mlchart.com/terminology/environment/litmus-paper/"
}