14. Using a mass spectrometer, a sample of an ancient wooden object was found to have a ratio of 14C to 12C equal to 3.3×10 -13 as compared to a current biological sample, which has a ratio of 14C to ¹2C of 1.2×10 −12 (Given: t, is 5730 years) What is the age of the object? 15. For the reaction, 2 A(g) + B₂(g) → 2 AB(g) The rate law is; rate = k[A][B₂]³ At 22.0 °C, k = 1234 M-³s-1. What would be the rate of the reaction if the concentration of A is 0.100 M and concentration of B₂ is 0.125 M.

An archaeologist finds some ancient jewelry made from bone. The jewelry has a carbon mass of 484 g (HINT: Assume all the carbon is 12C and determine the number of atoms, 12C has a molar mass of 12 g/mol) and careful measurements show that the remaining 14c has a current decay rate of 11 decays/s. Determine the age of the bone (and presumably the jewelry). The ratio of 14C to 12c when the animal died was 1.25x10-12 & the half-life of 14c is 5730 y. Additionally, 1 mol = 6.022x1023 365.25 days, & 1 day = 24 h. particles, 1 y = age of bone =

Archeologists continue to debate the arrival of the first humans in the Western Hemisphere. Radiocarbon dating of charcoal from a cave in Chile was used to establish the earliest date of human habitation in South America as 8700 years ago. This procedure involves comparing the 14C present in a sample of charcoal to the 14C present in a living tree of the same age. What fraction of the 14C initially present remained in the charcoal after 8700 years? The half-life of 14C is 5730 years. (Write the answer as a number with a decimal.)

In a leather sandal a mass spectrometer measures the Carbon 14 content of 8.3 E-11 % of all of the carbon isotope present. The approximate age of the sandal is?  Given that the half life of Carbon 14 is 5730 years  and of all of carbon isopotes present in living tissue, 1.66 E-10% are Carbon 14

​Strontium-90 is a radioactive material that decays according to the function A(t)=A0e−0.0244t, where A0 is the initial amount present and A is the amount present at time t​ (in years). Assume that a scientist has a sample of 500 grams of​strontium-90.   ​(a) What is the decay rate of​ strontium-90? ​(b) How much​ strontium-90 is left after 40​years? ​(c) When will only 300 grams of​ strontium-90 be​ left? ​(d) What is the​ half-life of​ strontium-90?

You’re wandering around and come upon an interesting looking rock. The rock is slightly radioactive, so you analyze it. The resulting data is as follows:Elapsed Time(s) / Counts0 / 96250 / 891100 / 718150 / 598200 / 531250 / 448300 / 413350 / 334400 / 308450 / 287500 / 202550 / 178600 / 154 a. Calculate the value of k using any two of the above data points.b. Use your value of k to determine the half-life of this sample.