Which of the following combinations will result in a reaction that is spontaneous at all temperatures? A: positive enthalpy change and positive entropy change B: positive enthalpy change and negative entropy change C: negative enthalpy change and positive entropy change D: negative enthalpy change and negative entropy change

Abullet found at a crime scene may be used as evidence in a trial if the percentage of metals match to the composition of metals in a bullet from the suspect's ammunition. a forensic scientist's analysis of the bullet shows that it contains 11.9 g of lead, 0.5 g of tin, and 0.8 b of antimony. what is the percentage of lead metal in the bullet? express your answers to the one's place.

Explain what happens at the saturation point when adding salt to water at room temperature.

How can carbon move from "land" to bodies of water? describe the way human impact has lead to increased levels of co2 in the atmosphere.