noun ·Rare ·Advanced level

Definitions

Noun

1. 1
   A naturally-occurring isotope of calcium, ⁴⁸₂₀Ca, with 20 protons and 28 neutrons. It decays very slowly, with a half-life of 4.3x10¹⁹ years. Because it is unusually neutron-rich, it is popular for the manufacture of superheavy elements. uncountable

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