Which of the following are formulations of the second law of thermodynamics?

A. It isn't possible to transfer heat from an object at a lower temperature to another object at a higher temperature unless work is done.

B. All systems can convert energy from one form to another useful form with 100% efficiency.

C. It isn't possible to change heat completely into work, with no other change taking place.

D. Entropy of a system decreases over time.

Asample of tin (ii) chloride has a mass of 0.49 g. after heating, it has a mass of 0.41 g.  what is the percent by mass of water in the hydrate?   %

Listenbase your answer to the question on the information below.nuclear radiation is harmful to living cells, particularly to fast-growing cells, such as cancer cells and blood cells. an external beam of the radiation emitted from a radioisotope can be directed on a small area of a person to destroy cancer cells within the body.cobalt-60 is an artificially produced radioisotope that emits gamma rays and beta particles. one hospital keeps a 100.0-gram sample of cobalt-60 in an appropriate, secure storage container for future cancer treatment.which choice represents the correct product for the beta decay of the co-60? fe-60ni-60fe-61ni-61

How many grams are in 68.2 molecules of br2?