CH4 (methane) + 202 (oxygen) → CO2 (carbon dioxide) + 2H20 (water) + Work + Heat
Which reactant is the main source of chemical potential energy in the chemical
reaction above?
CH4
202
2H20
CO2

put the answers   and i could answer.

1.43 x 10^-11 j the guy commented the awnser just making sure u see it .

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.