Potassium-argon dating is accurate from 4.3 billion years (the age of the Earth) to about 100,000 years before the present. At 100,000 years, only 0.0053% of the potassium-40 in a rock would have decayed to argon-40, pushing the limits of present detection devices.
How long does potassium-argon dating?
The potassium-argon age of some meteorites is as old as 4,500,000,000 years, and volcanic rocks as young as 20,000 years old have been measured by this method. This is possible in potassium-argon (K-Ar) dating, for example, because most minerals do not take argon
Is Argon-40 Stable?
Argon (Ar) has three natural isotopes with masses 36, 38, and 40. Ar and 38Ar are stable, that is, they are not radioactive, and they are also not produced by radioactivity processes.
What plants need a lot of potassium?
In short, potassium helps plants grown for their fruiting and flowering, including rose bushes and fruit trees, rather than plants grown for their foliage, such as spinach, lettuce and Swiss chard. Banana peels are good fertilizer because of what they do not contain.
What happens if you breathe in argon?
Argon is nontoxic and largely inert. It can act as a simple asphyxiant by displacing the oxygen in air to levels below that required to support life. Inhalation of argon in excessive amounts can cause dizziness, nausea, vomiting, loss of consciousness, and death.