The relative atomic mass of an element is: A. the mass of its atoms co pared to the mass of a carbon-12 atom.

B. The mass of its atoms averaged over time.

C. The mass of its isotopes compared to the mass of a normal atom.

D. The mass of only the neutrons in the atoms nucleas.​

Asolution is made by dissolving 25.5 grams of glucose (c6h12o6) in 398 grams of water. what is the freezing point depression of the solvent if the freezing point constant is -1.86 °c/m? show all of the work needed to solve this problem.

T(s) in2os] (m) 0 185 2.39 546 1.90 725 1.70 the decomposition of n205 can be described by the equation 2.68 given these data for the reaction at 45°c in carbon tetrachloride solution, calculate the average rate of reaction for each successive time interval. ntr s to 185 s 185 s to 546 s 546 s to 725 s number number number reaction rate: m/s m/s m/s

The chemical composition of soil varies with depth. an article in communications in soil science and plant analysis describes chemical analyses of soil taken from a farm in western australia. fifty specimens were each taken at depths 50 and 250 cm. at a depth of 50 cm, the average no3 concentration (in mg/l) was 88.5 with a standard deviation of 49.4. at a depth of 250 cm, the average concentration was 110.6 with a standard deviation of 51.5. find a 95% confidence interval for the difference in no3 concentrations at the two depths.