A scientist is using potassium-40, which is a radioactive isotope of potassium, to find the absolute age of a fossil by radiometric dating. The scientist determines that about three-fourths of the original potassium-40 atoms in the fossil now remain in the fossil. What additional information is necessary for the scientist to determine the absolute age of the fossil?
A. the half-life of potassium-40
B. the identity of an index fossil
C. the atomic mass of potassium-40
D. the total mass of the fossil

Where does all the water go? according to the environmental protection agency (epa), in a typical wetland environment, 39% of the water is outflow; 46% is seepage; 7% evaporates; and 8% remains as water volume in the ecosystem (reference: united states environmental protection agency case studies report 832-r-93-005). chloride compounds as residuals from residential areas are a problem for wetlands. suppose that in a particular wetland environment the following concentrations (mg/l) of chloride compounds were found: outflow, 60.4; seepage, 73.7; remaining due to evaporation, 26.4; in the water volume, 46.8. (a) compute the weighted average of chlorine compound concentration (mg/l) for this ecological system. (round your answer to one decimal place.) mg/l (b) suppose the epa has established an average chlorine compound concentration target of no more than 58 mg/l. does this wetlands system meet the target standard for chlorine compound concentration? yes. the average chlorine compound concentration (mg/l) is too high. yes. the average chlorine compound concentration (mg/l) is lower than the target. no. the average chlorine compound concentration (mg/l) is lower than the target. no. the average chlorine compound concentration (mg/l) is too high.

What is the difference between a meteoroid and a meteor?

Is a fossil fem that support wegener's hypothesis of continental drift a. gondwanded b. kannemerid c. mesosaurus d. glossopters