Radiometric dating practice questions
Last year, we posted a video explaining how to do three types of radiometric dating problems; we wrote about it in this blog post.I am pleased to report that the prodigious Matt Taylor has now released an activity with four sample problems that your students can work. In question #1, students are given the half-life and % of the isotope remaining and must figure out the age of the fossil.
And then either later in this video or in future videos we'll talk about how it's actually used to date things, how we use it actually figure out that that bone is 12,000 years old, or that person died 18,000 years ago, whatever it might be. So let me just draw the surface of the Earth like that. So then you have the Earth's atmosphere right over here. And 78%, the most abundant element in our atmosphere is nitrogen. And we don't write anything, because it has no protons down here. And what's interesting here is once you die, you're not going to get any new carbon-14. You can't just say all the carbon-14's on the left are going to decay and all the carbon-14's on the right aren't going to decay in that 5,730 years.
After all, textbooks, media, and museums glibly present ages of millions of years as fact.
Yet few people know how radiometric dating works or bother to ask what assumptions drive the conclusions. This figure wasn’t established by radiometric dating of the earth itself. Radiohalos shouldn’t exist, according to conventional wisdom!
Radiometric dating measures the decay of radioactive atoms to determine the age of a rock sample.
It is founded on unprovable assumptions such as 1) there has been no contamination and 2) the decay rate has remained constant.
Radiometric dating is very reliable in theory - the decay of radioactive materials is very-very predictable.