According to the law of conservation of Mass:
In a chemical reaction mass can neither be created nor be destroyed
So, we can say that: Mass of A + Mass of B = Mass of C
In the given reaction,
One of the reactants weigh 5 grams and another one weighs x grams
The mass of the product of this reaction is 9 grams
<u>Mass of reactant B:</u>
Mass of A + Mass of B = Mass of C
5 + x = 9
x = 4 grams
Well you want the answer with the same letter in it. A.k.a 2. This means they have the same element in them
O2 (Diatomic oxygen that we breathe) and O3 (Ozone that would be deadly to breathe) have different structures.
So the answer is 2
If you are a plato user the answer is D. vitamin E is fat soluble