Why do you think the chemical reactions lab we did is typically called a "copper plating lab"? a. because the acid solution cleaned the pennies and made the copper look shinier. b. because the acid solution cleaned the paperclips and made them look like pennies c. because the copper from the pennies was removed, and then added to the paperclips. d. because the copper from the paperclips was removed, and then added to the pennies.

(a) calculate the number of electrons in a small, electrically neutral silver pin that has a mass of 10.0 g. silver has 47 electrons per atom, and its molar mass is 107.87 g/mol. (b) imagine adding electrons to the pin until the negative charge has the very large value 1.00 mc. how many electrons are added for every 109 electrons already present

Asheet of steel 1.5 mm thick has nitrogen atmospheres on both sides at 1200oc and is permitted to achieve a steady-state diffusion condition. the diffusion coefficient for nitrogen in steel at this temperature is 6 x 10- 11 m2 /s, and the diffusion flux is found to be 1.2 x 10-7 kg/m2 -s. also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 4 kg/m3 . how far into the sheet from this high-pressure side will the concentration be 2.0 kg/m3 ? assume a linear concentration profile.

Write down two additional questions about earth's magnetic field that will make your presentation more informative.