19 lugl 1864 anni - John Newlands: Newlands was the first person to arrange each of the elements known at the time, periodically in the order of atomic mass. This arrangement allowed him to see that every eight elements had similarities which he called the law of octaves. No gaps were left for new elements.
Aggiunto al nastro di tempo:
Data:
19 lugl 1864 anni
Adesso
~ 161 years ago