Free mobile porn zambian sites - Falicies of radioactive dating
Some nuclides have very long half-lives, measured in billions or even trillions of years.
Others have extremely short half-lives, measured in tenths or hundredths of a second.
The decay rate and therefore the half-life are fixed characteristics of a nuclide. Thats the first axiom of radiometric dating techniques: the half-life of a given nuclide is a constant.
(Note that this doesnt mean the half-life of an element is a constant.
Since all atoms of the same element have the same number of protons, different nuclides of an element differ in the number of neutrons they contain.
For example, hydrogen-1 and hydrogen-2 are both nuclides of the element hydrogen, but hydrogen-1's nucleus contains only a proton, while hydrogen-2's nucleus contains a proton and a neutron.
Radiometric dating methods are the strongest direct evidence that geologists have for the age of the Earth.
All these methods point to Earth being very, very old -- several billions of years old.
In alpha decay, the radioactive atom emits an alpha particle.
An alpha particle contains two protons and two neutrons.
Protons and neutrons together are called nucleons, meaning particles that can appear in the atomic nucleus.Tags: Adult Dating, affair dating, sex dating