Pronunciation

/rəʊˈæktɪvəti/

Definitions

• Noun: The spontaneous emission of ionizing radiation by certain atomic nuclei or subatomic particles, characterized by the presence of radioactivity or radioactive decay. Oxford
• Verb: To exhibit or be affected by radioactivity; undergo radioactive decay. Cambridge

Phrases

• “Radioactive decay” refers to the process by which unstable atoms emit radiation.
• “Radioactivity levels” measure the intensity of radioactive substances.
• “Radioactive waste” is the byproduct of nuclear reactions containing radioactive materials.

Example Sentences

• Noun: “The sample showed high levels of radioactivity after being exposed to cosmic rays.”
• Verb: “The old reactor had been decommissioned due to its increased radioactivity over time.”
• “Scientists monitor the radioactivity of natural sources like granite to assess potential risks.”

Synonyms

• Radioactivity (no direct synonym, but related terms include “radioactive flux”, “radioisotopic activity”, “nuclear decay”)

Antonyms

• Stability (absence of radioactivity)

Notes

Radioactivity is a fundamental concept in physics and chemistry, with applications ranging from medical treatments to geologic dating. It is often associated with the phenomenon of nuclear fission and fusion, which powers both nuclear reactors and stars.