Methane has an atmospheric lifetime of about 10 years. However, estimates of the global warming potential from methane emissions assume a lifetime of 17 years for decay of this added methane. Why is that?

Which of the following is an example of initiation? Br- Br - heat Br Br • IV Br HBr O A. IV O B.I OC.I O D. II

Scientists can determine the age of ancient objects by the method of radiocarbon dating. The bombardment of the upper atmosphere by cosmic rays converts nitrogen to radioactive isotope of carbon, 14C, with a half-life of about 5730 years. Vegetation absorbs carbon dioxide through the atmosphere and animal life assimilates 14C through food chains. When a plant or animal dies, it stops replacing its carbon and the amount of ¹4C begins to decrease through radioactive decay. Therefore the level of radioactivity must also decay exponentially. A parchment fragment was discovered that had about 74% as much 14C radioactivity as does plant material on earth today. Estimate the age of the parchment. (Round your answer to the nearest whole number.) yr Need Help? Watch It Additional Materials eBook

31D 15 undo 'H → 32P+ ? 15 Express your answer as a particle. ? OA chemical reaction does not occur for this question.

The half life for the radioactive decay of carbon-14 to nitrogen-14 is 5.73 x 10° years. Suppose nuclear chemical analysis shows that there is 0.276 mmol of nitrogen-14 for every 1.000 mmol of carbon-14 in a certain sample of rock. Calculate the age of the rock. 圖 Round your answer to 2 significant digits. alo years Explanation Check O 2022 McGraw Hill LLC. All Rights Reserved. Terms of Use I Privacy Center| Accessibility IA (99+

The half life for the radioactive decay of carbon-14 to nitrogen-14 is 5.73 × 10° years. Suppose nuclear chemical analysis shows that there is 0.878 mmol of nitrogen-14 for every 1.000 mmol of carbon-14 in a certain sample of rock. Calculate the age of the rock. Round your answer to 2 significant digits. |years

A certain drug has a half-life in the body of 5.5 h. What should the interval between doses be, if the concentration of drug in the body should not fall below 35.% of its initial concentration? Round your answer to 2 significant digits.

. Let's apply the results of Problem 2 to potassium-argon dating frequently used to date sedimentary rocks. Potassium-40 decays by two different paths: electron emission electron capture where conversion to Ca occurs 89.1% of the time, and to Ar 10.9% of the time. The overall half-life for the decay of potassium-40 is 1.248 × 10⁹ years. Estimate the age of sedimentary rocks with an argon-40 to potassium-40 ratio of 1.02 %. 40 19K 140 Ca 40K 240 Ar 19 18-

What is the energy associated with the formation of 4.40 g of 4He by the fusion of 3H and 1H? Substance Mass (u) 4He 4.00260 3H 3.01605 1H 1.00783

6)  The 87Rb/87Sr method of dating rocks is used in geology.    a) Provide the balance reaction for 87Rb changing to 87Sr   b) The half-life for this process is 6.0 x 1010  A rock is found to have MOLE ratio of 87Rb to 87Sr of 36:1  How old is the rock?  (This is slightly easier than the one done in lecture because the two atoms in that one had different weights.)