Radioactive dating Definition and 14 Threads

When scientists use radioactive dating of elements in the asteroids to determine the age of the solar system, how do they know what the original amount of the radioactive element that was in the rock was? Do they need to know what the original amount of the radioactive element was in the rock...

Homework Statement Carbon-14 decays by β emission and has a half-life of 5570 years. What is the decay constant of carbon-14? What is the activity of 1 g of carbon if 1 in 1012 atoms are carbon-14? After what time will the activity per gram have fallen to 3 Bq? Homework Equations λt½ = ln(2)...

Hello, Are there any anthropologists, archaeologists, or geologists around on this board for help? I am trying to teach myself about radioactive decay via beta emission whereby a neutron spontaneously transmutes into a proton, releasing an electron. But, I do not understand the practical side...

I understand that it's possible to calculate the age of terrestial planets through radioactive dating their soil. However, the gas planets present a different challenge since we cannot currently land on them. Any ideas on how to calculate their ages in a different manner?

Homework Statement The isostopc abundances of a sample is U-235 and U-238 are 0.72 and 99.27 respectively; what is the age of the sample? (assume isotope abundance was equal when sample was formed) Homework Equations \lambda=\frac{ln2}{ t_{\frac{1}{2}}} The Attempt at a Solution for U-238...

Homework Statement Homework Equations N= (N_0) e^(-kT) k = ln(2)/(T_1/2) The Attempt at a Solution N0 = 7.5g T_1/2 = 22.3 years T = 17.5 years k = ln(2)/22.3 = .031 N = 7.5 e^(-.031 * 17.5) N = 4.36 g So I chose A, but the correct answer was B. can't figure out where I went wrong

Homework Statement The age of the dead sea scrolls was measured using radiocarbon dating. If the measurement gives a ratio of 0.78 for the ratio of the activity in the sample to the activity in a sample of corresponding live material of similar mass, calculate the age of the scrolls...

I apologize for the simplicity of this question in relation to the others on this site. But I've been curious, and haven't been able to find an answer. In Radioactive Dating, how do scientists know how much of a certain isotope (ie. Carbon-14, Potassium-40) was there to start with in an...

A sample of an ancient rock contains one atom of lead for every atom of uranium. the uranium in the rock has a half - life of 4500 million years. It decays to form lead which is not radioactive. Explain why the age of the rock is 4500 million years. I assumed that 1 x 4500 million years = 0.5...

These are just a few practice questions I found difficult, I would appreciate it if you could provide step-by-step explanation on how to solve the following problems. I checked all my answers in the textbook and got the following wrong, but cannot work out how to arrive at the right answer...

i am wondering if we know decays like Samarium-neodymium and Rubidium-strontium with half-lives of 106 and 49 billion years, why scientists consider the age of Earth based on Uranium-lead dating with half-life of 4.47 billion years? i mean if there wasn't Earth 100 billion years ago, where these...

Homework Statement A laboratory rat is exposed to an alpha-radiation source whose activity is 11.3 mCi. What is the activity of the radiation in disintegrations per second? in becquerels? The rat has a mass of 315 grams and is exposed to the radiation for 12.3 seconds, absorbing 39% of...

Hello my smart fellows, I was wondering why scientists say that when an ancient civilization constructs a structure, they can tell the date that the structure was built with radioactive dating methods? Surely the materials used to make the structure already HAD an age, so how would they be able...

[SOLVED] Radioactive Dating with Potassium Argon Homework Statement The technique known as potassium-argon dating is used to date old lava flows. The potassium isotope ^{40}{\rm K} has a 1.28 billion year half-life and is naturally present at very low levels. ^{40}{\rm K} decays by beta...