英和和英

語源

From radioactive +‎ -ity or radio- +‎ activity.

発音

• IPA: /ˌreɪdɪəʊakˈtɪvɪti/

名詞

radioactivity (usually uncountable, plural radioactivities)

1. Spontaneous emission of ionizing radiation as a consequence of a nuclear reaction, or directly from the breakdown of an unstable nucleus.
   • 2020 March 8, Jacopo Prisco, “When beauty products were radioactive”, in CNN‎:

     Today, no one would intentionally smear radioactive materials on their face, but in 1933, the dangers of radioactivity were not yet fully understood.

2. The radiation so emitted; including gamma rays, alpha particles, neutrons, electrons, positrons, etc.

下位語

(types of radioactive decay):

• alpha decay
• beta decay
• electron capture
• gamma decay
• spontaneous fission

派生語

関連する語

Units of radioactivity:

• becquerel
• curie

参考

• half-life

Further reading

• Radioactive decay on Wikipedia.Wikipedia