National Day
National Periodic Table Day
Celebrated on 02/07/2026
Quick Fact
National Periodic Table Day is celebrated on February 7th, honoring the date in 1863 when English chemist John Newlands published his 'Law of Octaves,' an early precursor to the modern periodic table. The holiday also recognizes Dmitri Mendeleev, who created the first widely accepted periodic table in 1869, famously predicting the properties of undiscovered elements.
Origins and Establishment of National Periodic Table Day
National Periodic Table Day was established by David T. Steinecker, a science educator and periodic table enthusiast, in 2016. Steinecker chose February 7th to commemorate John Newlands' 1863 publication of the Law of Octaves, which arranged elements by atomic weight and noted repeating patterns every eight elements. The day gained official recognition when the American Chemical Society (ACS) and other scientific organizations endorsed it, promoting it as a way to celebrate the foundational tool of chemistry.
Evolution and Modern Commemoration
Initially a grassroots effort among educators, National Periodic Table Day has grown into a global event celebrated by schools, museums, and science centers. Activities include interactive periodic table games, element scavenger hunts, and talks on element history. Since 2019, the ACS has hosted an annual online symposium featuring chemists and educators. The day also coincides with the United Nations' International Year of the Periodic Table in 2019, which amplified its reach. Today, social media campaigns using #NationalPeriodicTableDay share element facts and creative periodic table art.
Facts & General Observations
- The modern periodic table contains 118 confirmed elements, with the newest (element 118, Oganesson) added in 2016.
- Dmitri Mendeleev's 1869 table had only 63 elements, but he correctly predicted the properties of gallium, scandium, and germanium years before they were discovered.
- National Periodic Table Day is celebrated in over 50 countries, with events ranging from element-themed baking contests to building life-sized periodic tables.