Beta Decay of Potassium-40

40K → 40Ca + e− + ν̄e

概述

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.

参与者

角色 物质 系数 状态
反应物 Potassium K 1 (s)
产物 Calcium Ca 1 (s)

日常示例

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

工业重要性

K-Ar和Ar-Ar定年用于火山岩定年和建立地质年代尺度。K-40也是辐射探测中的本底辐射源。

属性

类型
Nuclear
可逆
否
能量
放热
ΔH
-130000000.0 kJ/mol

相关反应

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.