Mixture Problem A jeweler has five rings, each weigh- ing 18 g, made of an alloy of 10% silver and 90% gold. She decides to melt down the rings and add enough silver to reduce the gold content to 75%. How much silver should she add?

Use the periodic table to determine the electron configuration of dysprosium (dy) and americium (am) in noble-gas notation.

You just calculated that the heat of fusion for chloromethane is 6400 j/mol. the heat of fusion for hydrogen is 120 j/mol.? which of the following account for this difference? more than one correcta. chloromethane can absorb more energy at the same temperature. b. hydrogen has stronger intermolecular forces than chloromethane. c. hydrogen molecules can pack more closely than chloromethane molecules. d. chloromethane experiences dipole-dipole interactions. e. chloromethane has a higher molar mass than hydrogen.

Why is it possible for different microorganisms to extract energy not only from carbohydrates and other biological molecules but from a large variety of substances?