"potassium-40" meaning in English

{
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "potassium-40 (uncountable)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        {
          "kind": "other",
          "name": "English entries with incorrect language header",
          "parents": [
            "Entries with incorrect language header",
            "Entry maintenance"
          ],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with 1 entry",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "other",
          "name": "Pages with entries",
          "parents": [],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Forty",
          "orig": "en:Forty",
          "parents": [
            "Numbers",
            "All topics",
            "Terms by semantic function",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Isotopes",
          "orig": "en:Isotopes",
          "parents": [
            "Chemical elements",
            "Matter",
            "Chemistry",
            "Nature",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Potassium",
          "orig": "en:Potassium",
          "parents": [
            "Alkali metals",
            "Chemical elements",
            "Metals",
            "Matter",
            "Metallurgy",
            "Chemistry",
            "Nature",
            "Technology",
            "Sciences",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        },
        {
          "kind": "topical",
          "langcode": "en",
          "name": "Radioactivity",
          "orig": "en:Radioactivity",
          "parents": [
            "Nuclear physics",
            "Radiation",
            "Physics",
            "Quantum mechanics",
            "Energy",
            "Sciences",
            "Nature",
            "All topics",
            "Fundamental"
          ],
          "source": "w"
        }
      ],
      "glosses": [
        "A naturally-occurring radioactive isotope of potassium, ⁴⁰₁₉K, having nineteen protons and twenty-one neutrons, and a half-life of 1.3 billion years; it is the chief source of natural radioactivity in living tissue"
      ],
      "id": "en-potassium-40-en-noun-yZV6AkUG",
      "links": [
        [
          "physics",
          "physics"
        ],
        [
          "radioactive",
          "radioactive"
        ],
        [
          "isotope",
          "isotope"
        ],
        [
          "potassium",
          "potassium"
        ],
        [
          "proton",
          "proton"
        ],
        [
          "neutron",
          "neutron"
        ],
        [
          "half-life",
          "half-life"
        ]
      ],
      "raw_glosses": [
        "(physics) A naturally-occurring radioactive isotope of potassium, ⁴⁰₁₉K, having nineteen protons and twenty-one neutrons, and a half-life of 1.3 billion years; it is the chief source of natural radioactivity in living tissue"
      ],
      "tags": [
        "uncountable"
      ],
      "topics": [
        "natural-sciences",
        "physical-sciences",
        "physics"
      ],
      "wikipedia": [
        "Isotopes of potassium"
      ]
    }
  ],
  "word": "potassium-40"
}

{
  "head_templates": [
    {
      "args": {
        "1": "-"
      },
      "expansion": "potassium-40 (uncountable)",
      "name": "en-noun"
    }
  ],
  "lang": "English",
  "lang_code": "en",
  "pos": "noun",
  "senses": [
    {
      "categories": [
        "English entries with incorrect language header",
        "English lemmas",
        "English multiword terms",
        "English nouns",
        "English terms spelled with numbers",
        "English uncountable nouns",
        "Pages with 1 entry",
        "Pages with entries",
        "en:Forty",
        "en:Isotopes",
        "en:Potassium",
        "en:Radioactivity"
      ],
      "glosses": [
        "A naturally-occurring radioactive isotope of potassium, ⁴⁰₁₉K, having nineteen protons and twenty-one neutrons, and a half-life of 1.3 billion years; it is the chief source of natural radioactivity in living tissue"
      ],
      "links": [
        [
          "physics",
          "physics"
        ],
        [
          "radioactive",
          "radioactive"
        ],
        [
          "isotope",
          "isotope"
        ],
        [
          "potassium",
          "potassium"
        ],
        [
          "proton",
          "proton"
        ],
        [
          "neutron",
          "neutron"
        ],
        [
          "half-life",
          "half-life"
        ]
      ],
      "raw_glosses": [
        "(physics) A naturally-occurring radioactive isotope of potassium, ⁴⁰₁₉K, having nineteen protons and twenty-one neutrons, and a half-life of 1.3 billion years; it is the chief source of natural radioactivity in living tissue"
      ],
      "tags": [
        "uncountable"
      ],
      "topics": [
        "natural-sciences",
        "physical-sciences",
        "physics"
      ],
      "wikipedia": [
        "Isotopes of potassium"
      ]
    }
  ],
  "word": "potassium-40"
}