Estimate through calculation the loc of octane. assume the lfl is 1.28 vol. %. [16b] when purging an octane tank it is desired to lower the oxygen concentration 40% below the loc. the initial oxygen concentration in the tank is 30 volume percent. a vacuum system capable of 290 mm hg abs. is available. assuming atmospheric pressure is 1 atm and the inert contains 1000 ppm oxygen. how many purging cycles does it take?

answer: atomic mass was originally used to arrange elements on the periodic table, but is no longer used to organize the modern version.

explanation:

originally atomic mass was used to arrange elements on the periodic table from left to right in a row. each column then shows similar properties of elements of a group.

in modern periodic table, the atoms are arranged in increasing atomic number. as atomic number represents the number of protons in an atom which is unique for every atom.