The Periodic Table Is a Database With the Best Schema in Science

Mendeleev designed the periodic table in 1869 as a way to organize 63 known elements by atomic weight and chemical properties. He left gaps for elements that had not been discovered yet and predicted their properties. Every prediction was confirmed. It is the most successful data schema ever created. The schema Each element in the periodic table has these properties: const hydrogen = { atomicNumber : 1 , // Unique ID (proton count) symbol : ' H ' , // 1-2 letter abbreviation name : ' Hydrogen ' , // Full name atomicMass : 1.008 , // Average mass in amu category : ' nonmetal ' , // Classification group : 1 , // Column (1-18) period : 1 , // Row (1-7) electronConfig : ' 1s1 ' , // Electron shell arrangement electronegativity : 2.20 // Pauling scale }; The brilliance of the table's design: elements in the same column (group) have similar chemical properties because they have the same number of valence electrons. Group 1 (alkali metals) are all highly reactive. Group 18 (noble gases) are a