Word
radioactivity
Phoneticsra·dioac·tiv·i·ty
US/ˈɹeɪdioʊˌækˌtɪvəˌti/
UK/ɹˌeɪdɪəʊæktˈɪvɪti/
Definition
n. the process by which some materials give off energy and invisible rays. This happens because the atoms in these materials are unstable and change over time.
n. the spontaneous emission of ionizing radiation from the nucleus of an atom, typically as a result of radioactive decay.
Examples
“The scientist measured the radioactivity of the sample.”
“The nuclear power plant is designed to safely manage the radioactivity produced by the fission of uranium atoms.”
“While natural radioactivity is a constant background presence on Earth, the sudden increase in levels at the site raised significant concerns among the environmental monitoring team.”
Examples
simple
“The scientist measured the radioactivity of the sample.”
contextual
“The nuclear power plant is designed to safely manage the radioactivity produced by the fission of uranium atoms.”
complex
“While natural radioactivity is a constant background presence on Earth, the sudden increase in levels at the site raised significant concerns among the environmental monitoring team.”
Real-World Examples
“Each shipment should be checked for radioactivity when entering ports or crossing borders.” “Over that period, the detector recorded around 100 antineutrino candidate events linked to residual radioactivity in the reactor cores and nearby spent-fuel cooling pools.” Etymology
From radioactive + -ity or radio- + activity.
Etymology adapted from Wiktionary, available under CC BY-SA 4.0.
Word family
NOUN
ADJECTIVE
- Exam level
- CambridgeCambridgeCambridge English QualificationsThe exam suite from Cambridge University Press & Assessment, from A1 Movers up to C2 Proficiency. The benchmark names double as CEFR labels.C1 AdvancedIELTSIELTSInternational English Language Testing SystemThe 0–9 band test co-owned by the British Council, IDP, and Cambridge. Used for university entry, work, and migration.7.0–8.0TOEFL iBTTOEFL iBTTest of English as a Foreign Language, Internet-Based TestETS's academic English test, the standard route for US university admissions. Scored 0–120, with a 1–6 scale since 2026.1–6 scale: 5.0–5.595–113TOEICTOEICTest of English for International CommunicationETS's workplace English test, big in Japan and Korea. Listening & Reading scores 10–990 and tops out at C1.945–990
- Frequency
- Occasional
- Level
- C1 · Advanced
- Updated
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