Carbon 14 dating worksheet anwsers

The Slides are to be shown at the front and then each item is shown in turn and the pupils use their graphs to calculate the age of each item from the percentage of carbon found in them. take longer than you think, but keeps them engaged and there're questions to be answered in their books also.

carbon 14 dating worksheet anwsers-3

CARBON-14 IS CREATED (Figure 1a): When cosmic rays bombard the earth’s atmosphere, they produce neutrons.

These excited neutrons then collide with nitrogen atoms in the atmosphere, changing them into radioactive carbon-14 atoms.

To measure the rate of decay, a suitable detector records the number of beta particles ejected from a measured quantity of carbon over a period of time, say a month (for illustration purposes).

Since each beta particle represents one decayed carbon-14 atom, we know how many carbon-14 atoms decay during a month.

Carbon-14 can yield dates of only “thousands of years” before it all breaks down.

Although many people think radiocarbon dating is used to date rocks, it is limited to dating things that contain the element carbon and were once alive (like fossils).The carbon-14 in their bodies breaks down to nitrogen-14 and escapes at the same rate as new carbon-14 is added. CARBON-14 IS DEPLETED (Figure 1c): When an animal dies the carbon-14 continues to break down to nitrogen-14 and escapes, while no new carbon-14 is added.By comparing the surviving amount of carbon-14 to the original amount, scientists can calculate how long ago the animal died.Chemists have already determined how many atoms are in a given mass of each element, such as carbon.4 So if we weigh a lump of carbon, we can calculate how many carbon atoms are in it.If we know what fraction of the carbon atoms are radioactive, we can also calculate how many radiocarbon atoms are in the lump.In contrast, radiocarbon forms continually today in the earth’s upper atmosphere.

Tags: , ,