Editing Mendeleev's predicted elements (section)

{{short description|Elements predicted to exist but not yet found on the first periodic table}}
{{sidebar periodic table|history|image=Mendelejevs periodiska system 1871.png|caption=Mendeleev's 1871 periodic table}}
[[Dmitri Mendeleev]] published a [[periodic table]] of the [[chemical element]]s in 1869 based on properties that appeared with some regularity as he laid out the elements from lightest to heaviest.<ref>{{cite journal|last=Kaji|first=Masanori|title=D. I. Mendeleev's concept of chemical elements and ''The Principles of Chemistry''|journal=Bulletin for the History of Chemistry|volume=27|issue=1|pages=4–16|year=2002|url=http://www.scs.uiuc.edu/~mainzv/HIST/awards/OPA%20Papers/2005-Kaji.pdf|access-date=2006-11-09|archive-url=https://web.archive.org/web/20081217080509/http://www.scs.uiuc.edu/~mainzv/HIST/awards/OPA%20Papers/2005-Kaji.pdf|archive-date=2008-12-17|url-status=dead}}</ref> When Mendeleev proposed his periodic table, he noted gaps in the table and predicted that then-unknown elements existed with properties appropriate to fill those gaps. He named them eka-boron, eka-aluminium, eka-silicon, and eka-manganese, with respective atomic masses of 44, 68, 72, and 100.