What does a control group show in an experimental investigation? the effects that the scientists are causing by manipulating variables
how nature would act without manipulation by the researchers
why each part of a system is related to every other part
all parts of a system that scientists are controlling and changing

so she was walking and she stepped on warm jeffy , uh uh uhh dadye i just pooped my pants

answer carbon and three oxygen atoms;

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.