How did they figure out the periodic table of elements before they had electron microscopes?
Dear Straight Dope: I am wondering how in the world the person who developed the periodic table of elements was able to determine how many electrons and protons and such were in each elemental atom. This table was started in the days before electron microscopes and computers, so how did they know? I have asked science teachers and librarians but no one can answer this question. Surely you can. — Rich Stuemke You just have to know who to ask. The following was contributed by my son, currently working on a master’s degree in biochemistry: The short answer is, when they first developed the periodic table, they had NO IDEA how many protons or electrons were in each element. The original periodic table wasn’t based on the number of protons in each elemental atom, as it is today. The original periodic table, developed in 1871 by Dmitri Mendeleev, was based on the periodic law, which claimed at the time that repeating characteristics (hence, “periodicity”) are seen among the elements when the
