Using the knowledge that not all elements are eternal scientists came up with a method to date fossils and rocks.Radioactive isotopes fire off subatomic particles and energy.Yellow = Parent isotope Thorium 232 (45 beads), Purple = Daughter isotope Lead 208 (5 beads), Th-232 has a half-life of 14 billion years When class begins, tell the students that in this activity they will use their knowledge of radioactive decay and half-life properties to figure out the age of five different "fossils" at different stations around the room.The bag itself represents the fossil and the beads inside represent some of the millions of atoms that make it up.Next, label each bag with a number (1-5), put it at a separate station around the room, and make a sign that identifies the parent isotope type and color, daughter isotope type and color, and half-life. Blue = Parent isotope Uranium 235 (15 beads), Red = Daughter isotope Lead 207 (45 beads), U-235 has a half-life of 704 million years 2.For instance, your five bags might be set-up something like: Colors vary in the bags, but are marked on the baggies. Blue = Parent isotope Uranium 235 (5 beads), Red = Daughter isotope Lead 207 (35 beads), U-235 has a halflife of 704 million years 3.Technology also provides tools for investigations, inquiry, and analysis.

Technology is essential to science, because it provides instruments and techniques that enable observations of objects and phenomena that are otherwise unobservable due to factors such as quantity, distance, location, size, and speed.The lower down the canyon wall you go, the older the rock layers are.Therefore, fossils found in layers near the top of the canyon are younger than fossils found near the bottom of the canyon.Instead of using exponents and natural logs, the students can just use a graph of predicted decay rates to determine the number of half-lives the isotope has gone through based on this percentage (see graph).For instance, in fossil one, the students will take 15 divided by 60 and come up with the percentage.25 or 25%.

Technology is essential to science, because it provides instruments and techniques that enable observations of objects and phenomena that are otherwise unobservable due to factors such as quantity, distance, location, size, and speed.

The lower down the canyon wall you go, the older the rock layers are.

Therefore, fossils found in layers near the top of the canyon are younger than fossils found near the bottom of the canyon.

Instead of using exponents and natural logs, the students can just use a graph of predicted decay rates to determine the number of half-lives the isotope has gone through based on this percentage (see graph).

For instance, in fossil one, the students will take 15 divided by 60 and come up with the percentage.25 or 25%.

Students will calculate the percent of remaining parent isotopes using the following equation.