What evidence can be observed to determine when a chemical reaction takes place? (List all
6)

Elements in group 2 are all called alkaline earth metals. what is most similar about the alkaline earth metals?

The empirical formula of a compound is ch2o and its mass is 120 amu/molecule, what is its formula?

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?