Which of these items best describes the arrangement of electrons in an atom of sulfur? a. two electrons in its first energy level; two electrons in its second energy level; eight electrons in its third energy level; four valence electrons in its outermost energy level b. two electrons in its first energy level; eight electrons in its second energy level; six valence electrons in its outermost energy level c. two valence electrons in its first energy level; eight electrons in its second energy level; six electrons in its outermost energy level d. eight electrons in its first energy level; eight valence electrons in its outermost shell

Hot air balloons float in the air because of the difference in density between cold and hot air. in this problem, you will estimate the minimum temperature the gas inside the balloon needs to be, for it to take off. to do this, use the following variables and make these assumptions: the combined weight of the pilot basket together with that of the balloon fabric and other equipment is w. the volume of the hot air inside the balloon when it is inflated is v. the absolute temperature of the hot air at the bottom of the balloon is th (where th> tc). the absolute temperature of the cold air outside the balloon is tc and its density is ďc. the balloon is open at the bottom, so that the pressure inside and outside the balloon is the same. as always, treat air as an ideal gas. use g for the magnitude of the acceleration due to gravity.

This chart lists four kinds of polymers and their sources. what can be known about all four polymers, despite their differences? they come from living things. they share ionic carbon bonds. they are at least 100 monomers long. they are made of repeating subunits.

What term is applied to a scientist who studies ancient life, including animal and plant fossils a. anthropologist b. dendroclimatologist c. geophysicist d. paleontologist