How is radiometric dating used to tell the age of a fossil?

Answer 1

The radiometric dating method for organic matter that most people know about is carbon dating, and this method is limited to things less than about 60,000 years old. It will not do for a fossil, because the carbon-14 would be nearly all gone. In fact, for practical purposes, it would be all gone. And so would many or all of the materials that were in the animal or plant that left the fossil.

At the age given, the materials originally in a fossil are likely to have been replaced with other materials, so there would be likely to be very original material left to analyze. Also bear in mind that not all fossils are remains of living matter, for example, a remnant of a hole dug by an insect or worm could be a fossil.

Dating such old fossils can be done by dating the stone matrix in which they are found. This is done by comparing amounts of specific radioactive materials with amounts of other materials into which they decay. For example, potassium-40 decays into argon-40. With luck, meaning for example that the fossil has not been heated to much, we can compare the amounts of these substances in the rock to determine how long ago it became rock. That will tell us its age, give or take a twenty million years or so.

There are many similar combinations of isotopes that can be used, and the people doing the analysis would know which to use when they see what kind of rock is involved.

Answer 2

Scientist use certain atoms (carbon) which they know how long their half life is and how much mass has been or could be decayed in that range of time. So using the amount of decayed mass they can tell how old it is.

I hope that was understandable. ha..

Answer 3

For example, assume that a certain isotope (sub-type of an element) has a half-life of a million years, then after a million years only half of the substance is left, after two million years 1/4 of the original amount, etc.

To use this calculation requires knowledge of the original amount of the isotope present. It may also be possible to compare the amount left of an isotope, with the decay products (whatever the isotope converts into).

An isotope is a sub-type of an element: if two atoms have the same number of protons, but a different number of neutrons, they are considered to be of the same element (chemical properties are the same), but of different isotopes.

For example, assume that a certain isotope (sub-type of an element) has a half-life of a million years, then after a million years only half of the substance is left, after two million years 1/4 of the original amount, etc.

To use this calculation requires knowledge of the original amount of the isotope present. It may also be possible to compare the amount left of an isotope, with the decay products (whatever the isotope converts into).

An isotope is a sub-type of an element: if two atoms have the same number of protons, but a different number of neutrons, they are considered to be of the same element (chemical properties are the same), but of different isotopes.

For example, assume that a certain isotope (sub-type of an element) has a half-life of a million years, then after a million years only half of the substance is left, after two million years 1/4 of the original amount, etc.

To use this calculation requires knowledge of the original amount of the isotope present. It may also be possible to compare the amount left of an isotope, with the decay products (whatever the isotope converts into).

An isotope is a sub-type of an element: if two atoms have the same number of protons, but a different number of neutrons, they are considered to be of the same element (chemical properties are the same), but of different isotopes.

For example, assume that a certain isotope (sub-type of an element) has a half-life of a million years, then after a million years only half of the substance is left, after two million years 1/4 of the original amount, etc.

To use this calculation requires knowledge of the original amount of the isotope present. It may also be possible to compare the amount left of an isotope, with the decay products (whatever the isotope converts into).

An isotope is a sub-type of an element: if two atoms have the same number of protons, but a different number of neutrons, they are considered to be of the same element (chemical properties are the same), but of different isotopes.

Answer 4

As fossils age they slowly absorb radioactive elements and gasses. White Mouse Blood is injected into the fossil. Its is extreme resistant to radiation so they can detect even minute changes in the blood to better find the amounts of radiation, thus finding the fossils age.

Answer 5

For example, assume that a certain isotope (sub-type of an element) has a half-life of a million years, then after a million years only half of the substance is left, after two million years 1/4 of the original amount, etc.

To use this calculation requires knowledge of the original amount of the isotope present. It may also be possible to compare the amount left of an isotope, with the decay products (whatever the isotope converts into).

An isotope is a sub-type of an element: if two atoms have the same number of protons, but a different number of neutrons, they are considered to be of the same element (chemical properties are the same), but of different isotopes.

Answer 6

if you know the age of the fossil, you know the rock is from that time period

Answer 7

To find the age of rocks.