불안정한 원자핵이 스스로 붕괴하면서 방사선이나 입자를 방출하는 현상.
The spontaneous emission of ionizing radiation or particles resulting from the decay of unstable atomic nuclei.
예문:
"The rate of radioactivity in a sample is measured by the number of decays per second."
"Marie Curie's research on radioactivity earned her two Nobel Prizes."
방사성 물질이나 그 물질에서 나오는 유해한 방사선.
Radioactive substances or the ionizing radiation they emit, especially when considered as a pollutant or hazard.
예문:
"The government monitored the levels of radioactivity in the ocean after the power plant accident."
"Workers must wear lead-lined suits to protect themselves from high levels of radioactivity."