Answer:
They went from atoms to oxygen molecule.
Explanation:
I'm not sure if this is the answer your teacher is looking for, but in simple terms you had 2 oxygen atoms. Together they make an oxygen molecule, which is the stuff we breathe.
Answer:
Hydrogen is the most explosive element
It is not directly over a flame because it depends on the substance you might not want to heat it too much.you never know what could happen
The answer to your question is B.