Which of the following statments is true regarding the wave mechanical model of the atom?
a. orbitals describe how an electron moves in an atom.
b. orbitals give a probability map of where it is likely to find an electron in an atom.
c. the wave mechanical model only works for hydrogen and no other atoms.
d. orbitals give us the exact location of an electron in an atom.
e. orbitals are just like orbits in the bohr model.

Several kinds of bears are found on earth. most bears are brown or black, but one type of bear, the polar bear, is white. what process led to this difference in fur color? explain your answer.

Astudent is given a sample of a blue copper sulfate hydrate. he weighs the sample in a dry covered porcelain crucible and got a mass of 23.875 g for the crucible, lid, and sample. the mass of the empty crucible and lid was found earlier to be 22.652 g. he then heats the crucible to expel the water of hydration, keeping the crucible at red heat for 10 minutes with the lid slightly ajar. on colling, he finds the mass of crucible, lid, and contents to be 23.403 g. the sample was changed in the process to very light clue anhydrous cuso4. if there are again 100.0 g of hydrate, how many grams of cuso4 are in it? how many moles of cuso4? (hint: molar mass of cuso4 = 159.6 g / mole. what per cent of the hydrate is cuso4? you may convert the mass of cuso4 to moles.)

When a spring is compressed, the energy changes from kinetic to potential. which best describes what is causing this change?