Start Radiocarbon dating can be used to determine the age of

Radiocarbon dating can be used to determine the age of

Some half lives are several billion years long, and others are as short as a ten-thousandth of a second.

Students not only want to know how old a fossil is, but they want to know how that age was determined.

Some very straightforward principles are used to determine the age of fossils.

Where the amounts of parent and daughter isotopes can be accurately measured, the ratio can be used to determine how old the rock is, as shown in the following activities.

Part 2a Activity — At any moment there is a small chance that each of the nuclei of U-235 will suddenly decay.

In other words, during 704 million years, half the U-235 atoms that existed at the beginning of that time will decay to Pb-207. Many elements have some isotopes that are unstable, essentially because they have too many neutrons to be balanced by the number of protons in the nucleus.

Each of these unstable isotopes has its own characteristic half life.

On a piece of notebook paper, each piece should be placed with the printed M facing down. The candy should be poured into a container large enough for them to bounce around freely, it should be shaken thoroughly, then poured back onto the paper so that it is spread out instead of making a pile.

This first time of shaking represents one half life, and all those pieces of candy that have the printed M facing up represent a change to the daughter isotope.

The teacher should tell the students that there are two basic principles used by geologists to determine the sequence of ages of rocks.

They are: Principle of superposition: Younger sedimentary rocks are deposited on top of older sedimentary rocks.

4) To demonstrate how the rate of radioactive decay and the buildup of the resulting decay product is used in radiometric dating of rocks. (A single watch or clock for the entire class will do.) 6) Piece of paper marked TIME and indicating either 2, 4, 6, 8, or 10 minutes.