Fill in the blank for the correct number of molecules to balance the chemical equation: C6H12O6 + ______O2 ----------------------> _____CO2...

The correct chemical equation
is:

C6H12O6   +   6 O2 -->  6 CO2   +   6
H20

Chemical equations must balance so that
there are always equal numbers of atoms of each type on the left (reactants) and on the
right (products).  Balanced chemical equations show the number of moles of each reactant
and product in the reaction. This ensures that there are equal numbers of atoms of every
element on both sides of the equation.