Find the mass of 7.00 mol of H2O2?

238g

Explanation:

Molar Mass (1 mol) of H2O2 = 34.0147 g/mol

7.00 mol = 35.0147*7

= 238.1029g

= 238g (rounded to 3 sig figs because 3 sig figs in 7,00)

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.