Experimentation is the best way to obtain knowledge, because it is the only actual factual thing in the options
Answer:
technically two because the self-pollination thingy doesn't have anything to do with the number of parents
I believe it is A because a physical change is something that can be changed back to where a chemical change can not be such as burning something.
Answer:
Fe: 23.1%
N: 17.4%
O: 59.5%
Explanation:
You take the grams that each weigh on the periodic table and add it all up. Afterward you create fractions of each over the whole. (Example: Fe/Fe+N+O) then you divide and turn that decimal into a percentage.