Given the balanced equation representing a redox reaction:
2al + 3cu2+ --> 2al3+ + 3cu
which statement is true about this reaction?
(1) each al loses 2e- and each cu2+ gains 3e-
(2) each al loses 3e- and each cu2+ gains 2e-
(3) each al3+ gains 2e- and each cu loses 3e-
(4) each al3+ gains 3e- and each cu loses 2e-

The enthalpy of formation of water is -285.8 kj/mol. what can be inferred from this statement?

Dying the folding patterns of protein molecules can microbiologists better understand cellular processes as well as some diseases, such as alzheimer’s, that are caused by proteins that have misfolded. the folding of these complicated molecules can be simulated on computers, but it takes a lot of processor power and time for even expensive supercomputers to do this. a group of researchers at stanford university developed software that can be used to distribute the processing of data to anyone who is willing to donate time on their idle personal computers. as a result, the researchers have been able to achieve protein-folding simulations that are far better than those other computing methods have done. which statement best describes the work of these researchers? the work is not scientific because the data are not processed in one location. the work is not scientific because the simulations are not reproducible. the researchers applied creativity to solve a problem in running an experiment. the researchers used only well-established scientific techniques.

Which of the following observations indicates that there is a small, dense, positively charged part in the center of an atom? some uncharged particles are scattered by a gold foil. all uncharged particles are attracted towards a gold foil. all positively charged particles pass straight through a gold foil. some positively charged particles bounce back from a gold foil.