Answer:
Got what wrong? A question?
Answer: It is Mole.
Explanation:
Mole is the SI unit of measurement used to measure the number of things, usually atoms or molecules. One mole of something is equal to 6.02214078×1023 of same things (Avogadro's number).
<span> The production of absorption and emission lines . The first theory of the atom to provide an explanation of </span>hydrogen's<span> observed </span>spectral lines<span> those two energy levels, the electron </span>can<span> exist only in </span>certain<span> sharply defined . The </span>number<span> of protons in the nucleus of an atom determines the </span>element<span> that </span>