Radioactive dating for kids

If half of the uranium-238 has turned into lead-206 the rock will be 4500 million years old. Many of us believed that string theory was a very dramatic break with our previous notions of quantum theory.

As it turns out, nearly every element from Hydrogen (Z=1) to Bismuth (Z=83) has at least one stable isotope, with Technetium (Z=43) and Promethium (Z=61) as the exceptions.

All elements above Bismuth in the Periodic Table are unstable, i.e., they are in a constant state of releasing energy, or Each nucleus that alpha decays produces a unique set of alpha-particle energies.

Because these families have the same number of protons in the nucleus, they also have the same number of electrons orbiting the nucleus and thus exhibit the same chemical behavior.

It is the differing number of neutrons that give rise to stable and unstable isotopes (radioisotopes) within a given elemental family.

As these alpha particles travel through a mineral matrix, they deposit their energy in the mineral itself.

This energy damages the crystalline structure of the mineral and leaves in its wake a signature in the form of a series of discolored concentric rings—radiohalos—characteristic of the radionuclide that produced the alpha particles.

By comparing how much carbon-14 there is in the dead organism with the amount in a living one, the age of the dead organism can be estimated.

The half-life of uranium-238 is 4500 million years.

The age of the rock can be calculated if the ratio of uranium to lead is known.

As the rock gets older the proportion of lead increases.

Diffusion rates of the Thus, the observed evidence in rocks extracted from the earth’s crust present several conundrums—problems that center on assumptions made in using radioisotope decay within a rock sample as a clock to date the origins of that sample.

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