Radon gas as rn-222 is formed by the radioactive decay of u-238, the chief natural isotope of uranium, found in soils and especially granitic rocks. as rn-222, radon decays through several daughter-product isotopes to stable pb-2016. the gas occurs in air at natural levels of 0.1 to 0.2 pci/l, and is considered a health hazard (cancer risk) by the u. s. environmental protection agency at or above 4 pci/l in air. rn-222 decays by the emission of alpha particles (helium nuclei) with a half-life or decay half-time of 3.823 days.
(a) what is its decay rate constant in s-1?
(b) the mole fraction solubility of pure radon gas in water (nrn) from 3 to 970c at 1 atm radon gas pressure, is given by the equation
r in nrn = -499.309 + (25864.2/t) + 69.3241 in t + 0.00101227 t
where r = 1.9872 cal/mol k, and t is in degrees k. calculate the henry's law constant for rn gas at 250 c in m/bar?
(c) well waters pumped from granitic rocks or uraniferous sandstones may be high in radon. exsolution of the gas into the air in a shower stall may result in air levels in excess of 4pci/l. what m concentration of dissolved rn in a groundwater would be in equilibrium with 4 pci/l of radon gas in bathroom air at 250c.

the answer is c i believe

most historians agree that gabriel mouton, the vicar of st. paul’s church in lyons, france, is the “founding father” of the metric system. he proposed a decimal system of measurement in 1670. mouton based it on the length of one minute of arc of a great circle of the earth (now called a nautical mile, 1852 meters). he also proposed the swing-length of a pendulum with a frequency of one beat per second as the unit of length (about 25 cm). a pendulum beating with this length would have been fairly easy to produce, thus facilitating the widespread distribution of uniform standards. over the years, his work was revised, improved, and extended by a number of french scientists.

the political sponsor of weights and measures reform in the french revolutionary national assembly was the bishop of autun, better known as talleyrand. under his auspices, the french academy appointed several committees to carry out the work of developing a usable system of weights and measures for france. one of the committees recommended a decimalized measurement system based upon a length equal to one ten-millionth of the length of a quadrant of the earth’s meridian (i.e., one ten-millionth of the distance between the equator and the north pole).