Beta Decay of Potassium-40

40K → 40Ca + e− + ν̄e

概要

Potassium-40 decays to calcium-40 by beta emission (89.3%) or to argon-40 by electron capture (10.7%). With a half-life of 1.25 billion years, K-40 is the largest source of natural radioactivity in the human body. K-Ar dating is used for rocks millions to billions of years old.

参加者

役割 物質 係数 状態
反応物 Potassium K 1 (s)
生成物 Calcium Ca 1 (s)

日常の例

Every human body contains about 4,400 Bq of K-40 radioactivity from potassium in food, primarily from bananas, potatoes, and meat.

産業上の重要性

K-Ar年代測定とAr-Ar年代測定は、火山岩の年代を測定し地質年代尺度を確立するために使用されています。K-40は放射線検出におけるバックグラウンド放射線源でもあります。

特性

タイプ
Nuclear
可逆的
いいえ
エネルギー
発熱性
ΔH
-130000000.0 kJ/mol

関連する反応

Alpha Decay of Radium-226 Alpha Decay of Radon-222 Alpha Decay of Thorium-232 Neutron Capture by Uranium-238 Beta Decay of Iodine-131 Beta Decay of Strontium-90 Alpha Decay of Polonium-210 Americium-241 Alpha Decay Beta Decay of Cobalt-60 Electron Capture by Beryllium-7

Frequently Asked Questions

What is the equation for Beta Decay of Potassium-40?
The balanced equation is: ⁴⁰K → ⁴⁰Ca + e⁻ + ν̄ₑ.
What type of reaction is Beta Decay of Potassium-40?
Beta Decay of Potassium-40 is a nuclear reaction.
Is Beta Decay of Potassium-40 exothermic or endothermic?
Beta Decay of Potassium-40 is exothermic (releases energy). The enthalpy change (ΔH) is -130000000.0 kJ/mol.