Which is the preserved evidence of the activity of an organism?

How does the digestive system interact with the circulatory system? a. messages sent as electrical impulses from the digestive system are transported throughout the body by the circulatory system. b. nutrients taken in and broken down by the digestive system are carried to various parts of the body by the circulatory system. c. nutrients and gases are absorbed by organs in the circulatory system. then, they are transported to all parts of the body by organs in the digestive system. d. oxygen and carbon dioxide are exchanged by organs in the digestive system, and the gases are carried to the rest of the body by the circulatory system.

Solid tin exists in two forms: white and gray. for the transformation sn(s, white) → sn(s, gray) the enthalpy change is -2.1 kj/mol and the entropy change is -7.4 j/(mol*k). a. calculate the gibbs free energy change for the conversion of 1.00 mol white tin to gray tin at -30℃. b. will white tin convert spontaneously to gray tin at -30℃? c. at what temperature are white and gray tin thermodynamically equivalent at a pressure of 1 atm?

Identify the limiting reactant when 9.65-g h2so4 reacts with 6.10-g of naoh.the equation is h2s04 + 2naoh = 2h2o + na2so4• what is the theoretical yield of na2so4, in grams? • how much of the excess reagent will remain after the reaction has been completed? • if 10.5-g of na2so4 are actually recovered experimentally, what is the percent yield?