En Amerikansk oppgave
Posted: 03/04-2006 18:28
Jeg lurte litt på hvordan man løser denne oppgaven, fra en Amerikansk lærebok. Dette er for 1MX.
Jeg siterer:
"Volcanic eruptions can be dated by analyzing the potassium and argon contents of rock from the eruption. Most rocks contain potassium (K), 0,012 of which is K-40, a radioactive isotope that decays to Ar-40 (argon) with a half-life of 1,3*10^9 years. Since argon is an inert gas, it is likely that all of the argon in the rock originates from the decay of K-40. Suppose that a test of rock shows that the ratio of the number of non-decayed K-40 and Ar-40 isotpoes is to be 10 : 1.
When did the eruption take place?"
På forhånd takk.
Jeg siterer:
"Volcanic eruptions can be dated by analyzing the potassium and argon contents of rock from the eruption. Most rocks contain potassium (K), 0,012 of which is K-40, a radioactive isotope that decays to Ar-40 (argon) with a half-life of 1,3*10^9 years. Since argon is an inert gas, it is likely that all of the argon in the rock originates from the decay of K-40. Suppose that a test of rock shows that the ratio of the number of non-decayed K-40 and Ar-40 isotpoes is to be 10 : 1.
When did the eruption take place?"
På forhånd takk.