No, if H2O is separated into H2 and O, then it is not the same substance
Answer:A
Explanation: I learned it from a gizmo
An enzyme is a catalyst that helps speed up a chemical reaction.
Answer is: c. CuSO4 + 2NaOH yields Cu(OH)2 + Na2SO4.
Copper atom has oxidation number +2, sulfur atom oxidation number +6, oxygen has oxidation number-2, sodium has oxidation number +1 and hydrogen has +1 on both side of chemical reaction, so elements did not change their oxidation numbers.
