SI Units

Becquerel

Définition

L'unité SI de radioactivité, égale à une désintégration nucléaire par seconde (1 Bq = 1 s⁻¹).

Explication

Named after Henri Becquerel, who discovered radioactivity in 1896. The human body contains about 8,000 Bq of radioactivity from potassium-40 and carbon-14. The older unit curie (Ci) equals 3.7×10¹⁰ Bq. Fukushima reactor cores at peak released roughly 10¹⁸ Bq (1 exabecquerel). Safe drinking water limits are typically set at a few Bq/L.

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RELATED TERMS

Mètre

L'unité SI de base de longueur, définie comme la distance parcourue par la lumière en 1/299 792 458 de seconde.

Kilogramme

L'unité SI de base de masse, définie par la constante de Planck.

Seconde

L'unité SI de base du temps, définie par les transitions de l'atome de césium-133.

Kelvin

L'unité SI de base de température thermodynamique, dont l'origine est le zéro absolu.

Ampère

L'unité SI de base du courant électrique.