This year we celebrate the 150 th anniversary of Mendeleev’s achievement in formulating the ... The final piece in the puzzle wasn’t found until 1913, when Henry Moseley carried out work into the ...

His father died while he was young, and so his mother moved the family 1500 km to St. Petersburg, where she managed to get Dmitri into ... which didn’t work. Mendeleev had seen that they needed to be ...