Explanation:
D. The total mass of the reactants equals the total mass of the
products.
What are the answer choices?
Auroras occur when ions from the Sun strike air molecules, causing them to give off bright colors of light.-google
Oxidation number is charge of element in compound. Can be neutral, positive or negative.
Oxygen in dichromate has oxidation number -2, becauce there are seven oxygens, net oxidation number of oxygen is -14.
2·x(oxidation number of Cr) + 7· (-2) = -2 2x= +12
x= +6, oxidation number of one chromium is +6.