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How Do Scientists Determine The Age Of Fossils Using Radioactive Dating? (RESOLVED)

Researchers look for levels of carbon-14 in samples that contain human remains or artifacts dating back at least 50,000 years. Also called “radiocarbon,” this isotope is generated by cosmic rays colliding with nitrogen in Earth’s atmosphere, says José Capriles, an archaeologist at Pennsylvania State University. Chemically, carbon 14 behaves exactly like its stable siblings (carbon 12 and carbon 13), allowing plants to absorb it during photosynthesis and then pass it up the food chain 👍 While alive, animals and plants tend to contain the same levels of carbon 14 as their environment 😁 But “as living organisms die, they stop consuming or incorporating radiocarbon,” Capriles says, and “the process of radioactivity kicks in,” with the isotope decaying back into nitrogen. To determine the time since the death of an organism, researchers compare the amounts of carbon 14 and carbon 12. [1]
Before we had better methods to date fossils in the early days, paleontologists and geologists used relative dating techniques. To determine the order of sedimentary rocks, they looked at their position. Imagine your laundry basket—the dirty clothes you wore last weekend sit at the bottom, but today’s rest on top of the pile. This is how sedimentary rocks work. Younger rocks will be on the top, while older ones will be on bottom. To establish relative ages, researchers also utilized biostratigraphy. Biostratigraphy involves studying how fossils form, multiply, and then disappear from the rock record. As a way to first date fossils, we still use relative dating before assigning numerical or absolute ages. [2]
Image #2
Whittney Lau, according to science.howstuffworks.comAn atom may contain equal amounts of protons or neutrons. However, atoms may have too many neutrons or not enough protons. This makes them unstable and causes them to lose particles until their nucleus is stable. You can think of the nucleus like a stack of blocks. You can add blocks to either side of the pyramid. They may remain put for a time, but eventually they will fall apart. It’s the same if you remove a block from one pyramid side, making it unstable. Some blocks will eventually fall off, creating a stable, smaller structure. Modified by Ellise McHado, November 18, 2021 [3]
Trace amounts of isotopes of radioactive elements, including carbon-14, uranium-238, and dozens of others, are all around us—in rocks, in water, and in the air (Table 1). These isotopes are unstable, so they gradually break apart or “decay.” Radiometric dating Because radioactive elements decompose in predictable ways, just like a clock’s ticking. Here’s how it works. If you have a collection of one million atoms of a radioactive isotope, half of them will decay over a span of time called the “half life.” Uranium-238, for example, has a half life of 4.468 billion years, so if you start with a million atoms and come back in 4.468 billion years, you’ll find only about 500,000 atoms of uranium-238 remaining. Rest of the uranium is likely to have decomposed to about 500,000 other elements and eventually to nonradioactive atoms like lead-206. Just wait for another 4.468 million years before there will still be about 250,000 of these uranium atoms (Fig. 8). For their most recent revision, credit goes to Autumn Broussard (Istanbul, Turkey) [4]
The new report is by ucmp.berkeley.edu This clarifies the difference between two kinds of age determinations. To determine the relative age of rocks layers, geologists used fossils from them in the last 18th and first 19th centuries. William Smith was one the most influential geologists. important scientists from this time who helped to develop Through studying the distribution of fossils through the sedimentary rocks of southern England, we can gain knowledge about the evolution of these species. The amount of information about how fast the fossils were decaying was not available until late in the 20th Century. radioactive decay that the age of rocks and fossils in number of years could be determined through radiometric age dating. [5]

Refer to the Article

  1. https://www.scientificamerican.com/article/how-do-scientists-determine-the-ages-of-human-ancestors-fossilized-dinosaurs-and-other-organisms/
  2. https://www.smithsonianmag.com/smithsonian-institution/how-do-scientists-date-fossils-180972391/
  3. https://science.howstuffworks.com/environmental/earth/geology/dinosaur-bone-age.htm
  4. https://evolution-outreach.biomedcentral.com/articles/10.1007/s12052-010-0226-0
  5. https://ucmp.berkeley.edu/fosrec/McKinney.html
Mae Chow

Written by Mae Chow

Passionate about writing and studying Chinese, I blog about anything from fashion to food. And of course, study chinese! I'm a passionate blogger and life enthusiast who loves to share my thoughts, views and opinions with the world. I share things that are close to my heart as well as topics from all over the world.

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