The date below shows the concentration of N2O5 versus time forthe following reaction:
N2O5(g)---> NO3(g) +NO2(g)
Time(s) (N2O5)(M)
0 1.000
25 0.822
50 0.677
75 0.557
100 0.458
125 0.377
150 0.310
175 0.255
200 0.210
Determine the order of the reaction and the value of the rateconstant. Predict the concentration of N2O5 at 250s.

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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.