# Potassium 40 Argon 40 Dating

Plutonium-241, Bismuth-209, 2.4 Million. Thorium-232, Lead-208, 13.9 Billion. Potassium-40, Argon-40, 1.25 Billion. Potassium-40, Calcium-40, 1.4 Billion.

Potassium-Argon Radiodating Theory. (1) The radioisotope 40K constitutes 0.012 of all naturally occurring potassium. S.T. Butler H. Messel, A Modern. Since K-Ar (potassium-argon) dating is one of the most. About 110,000 of potassium is K40, which. Since K-Ar (potassium-argon) dating is one of the most. About 110,000 of potassium is K40, which. Its decay yields argon-40 and calcium-40 in a ratio of 11 to 89. The K-Ar method works by counting these radiogenic 40Ar atoms trapped inside. Its decay yields argon-40 and calcium-40 in a ratio of 11 to 89. The K-Ar method works by counting these radiogenic 40Ar atoms trapped inside. Precise measurements of the amount of 40K relative to 40Ar in an igneous rock can tell us the amount of time that has passed since the rock. Principles of Radiometric Dating. Naturally-occurring. Potassium 40. Glauconite contains potassium, so it can be dated using the potassium-argon technique. But, for the purposes of the KAr dating system, the relative abundance of 40K is so small and its half-life is so long. Potassium occurs naturally as three isotopes. The radioactive potassium-40 decays by two modes, by beta decay to 40Ca and by electron capture to 40Ar. There. Potassium occurs naturally as three isotopes. The radioactive potassium-40 decays by two modes, by beta decay to 40Ca and by electron capture to 40Ar. There. Precise measurements of the amount of 40K relative to 40Ar in an igneous rock can tell us the amount of time that has passed since the rock.