(SK015) Naturally occurring argon consists of thre isotopes , argon-36, argon-38, argon-40 in the ratio of 4.86: 1 : 1423 i) Calculate the percentage composition of the three isotopes. ii) Calculate the relative atomic mass of argon to four significant figures.

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.