Answer:
d is the answer of this question
It's where chemical elements are organized based on atomic weight. Also, like/similar physical and chemical properties in each interval of 7 elements.
It was a silly reason it was rejected. It was rejected because it's octaves were too similar to those in music.
I hope this helps!
If the energy level of a certain element is filled based on the maximum number of allowable electrons per level, then it is no longer reactive. With this, half-filled energy level means that the element may retain those electrons and attract electrons from other elements or it may give off its electrons.
