Which is NOT represented in a chemical change demonstrated chemical reactions?

Option C

Explanation:

A) A chemical equation is simply the symbolic representation of a chemical reaction using the form of symbols and formulae. Thus, option A is not the answer.

B) A product is the substance that shows at the end of a chemical reaction. Thus, option B is not the answer.

C) Law of conservation of mass in chemistry states that even in chemical reactions or physical transformations, that mass cannot be created nor destroyed. Which means that mass is conserved. This has nothing to do with chemical change demonstrated chemical reactions. Thus, option C is correct.

D) reaction rate is the speed that a chemical reaction occurs. Thus, options D is not correct.

"among the transition metal elements, manganese and zinc have a slight lowering of electronegativities. the reason behind this is that the nuclear charges of these elements are slightly weaker than the other transition metal elements due to the way their valence electrons are filled up. both manganese and zinc have their valence electrons filled up to the 4th shell with 1 pair of electrons (4s2) completely occupying it. although the electrons in the 3rd shell (3d) are yet to be paired since the outer most shell is filled up, the ability of the nucleus to attract electrons is lessened. hence,   the electronegativity (or the ability to attract electrons) is lessened."