plural of 419 scammer

plural of C-47

plural of top 40

(physics) An artificially produced radioactive isotope of potassium, ⁴²₁₉K, having a half-life of 12.4 hours; used in medicine as a tracer

(physics) A naturally-occurring radioactive isotope of potassium, ⁴⁰₁₉K, having nineteen protons and twenty-one neutrons, and a half-life of 1.3 billion years; it is the chief source of natural radioactivity in living tissue

(physics) An artificially produced radioactive isotope of potassium, ⁴³₁₉K, having a half-life of 22 hours; used in medicine as a tracer

(physics) A minor stable isotope of calcium, ⁴⁴₂₀Ca, having twenty protons and twenty-four neutrons; it amounts to about 2% of the element in nature

(physics) The major stable isotope of argon, ⁴⁰₁₈Ar, having eighteen protons and twenty-two neutrons; it amounts to about 99.6% of the element in nature

(physics) A naturally-occurring radioactive isotope of calcium, ⁴⁸₂₀Ca, having twenty protons and twenty-eight neutrons, and a half-life of 4.3x10¹⁹ years

(physics) A minor stable isotope of calcium, ⁴³₂₀Ca, having twenty protons and twenty-three neutrons; it amounts to about 0.1% of the element in nature