←Ar   Na↑   ↓Cu   Ca→

Kalium ∙ potassium ∙ potassio ∙ potasio
group I: R₂O

• melting point: 63.25°C
• boiling point: 759.9°C
• density: 0.862 g/cm³

Potassium nitrate (KNO₃) or saltpetre is a common oxidizers used in fireworks. — Periodic Table of Fireworks

The isotopic abundance of ⁴⁰K is 117.1 ppm
1000 mg K → √ 1000  Bq ⁴⁰K

☢ radioisotopes:
K-40 (T1/2=1.25 Ga) NORM

⁴⁰K measurements on Swiss college students gave 70 Bq/kg (m) / 55 Bq/kg (f) — URA-JB