Chemical evidence for chain folding in polyethylene crystals is obtained by etching polymer crystals with fuming nitric acid, which cleaves the chain at the fold surface. the resulting chain fragments are separated chromatographically and their molecular weights determined by osmometry. the folded chain is pictured as crossing through the crystal, emerging and folding back, then reentering and recrossing the crystal, and so on. according to this picture, the shortest chain showing up in the chromatograms should equal the crystal thickness in length. the second shortest chain exceeds twice this value by some amount, which measures the length of the loop made by the chain outside the crystal. molecular weights for the two shortest chains observed in an experiment of this sort were 1260 and 2530. since the cleaved chains end in nitro and carboxyl groups, 60 should be subtracted from each of these molecular weights to give polyethylene chain weight. calculate the degree of polymerization of each molecule and the chain length (use the length of the unit cell along the chain axis, 2.53 å, as the distance per repeat unit). compare the latter with the crystal thickness determined by x-ray diffraction, 105 å. what does the ratio of chain lengths for the first and second peaks suggest about the tightness of folding

when atmosphere interacts with biosphere they focuses on on the sources and sinks of green house gases (ghgs) air pollutants, particular matters, water and energy between the earth's surface and the atmosphere. the biosphere affects the climate. the atmosphere and biosphere are in constant interaction with each other, and all living things rely on gases in the atmosphere for life. organisms such as animals take in oxygen gas form the atmosphere to use in every cell of their body for smooth functioning of daily routine exercises.

explanation:

metals have excess of electrons whereas non-metals have deficiency of electrons. thus, in order to gain stability metals easily donate their electrons to the non-metals.

for example, electronic configuration of sodium is and electronic configuration of phosphorous is .

when a phosphorous atom and sodium atom combine together then sodium will donate is extra one electron to the phosphorous atom. as a result there will be formation of ionic bond between sodium and phosphorous.

the reaction will be as follows.

there, are three sodium sodium atoms and each of them will donate its one extra electron to phosphorous atom. thus, the sub-shell of phosphorous gets completely filled.  

thus, we can conclude that electrons are transferred from atoms of sodium to atoms of phosphorous. this transfer makes the sodium atoms donate one electron and the phosphorous atoms to gain one electron. as a result, the sodium and phosphorus atoms strongly attract each other.