History of the periodic table

• Mendeleev's Periodic Table had 63 elements listed with their properties and uses.
• Dmitri Mendeleev arranged elements based on their atomic weight, but he left gaps where there were missing elements.
• The first modern version of the periodic table was published by Dmitri Mendeleev in 1869.
• In 1870…


  John Newlands proposed that elements could be arranged in groups according to increasing atomic weight, with every eighth element having similar chemical properties.
• Dmitri Mendeleev published his first version of the periodic table in 1869, which included gaps for undiscovered elements.
• Mendeleev's periodic table had gaps where elements were not yet discovered, but he predicted their properties based on his understanding of atomic structure.
• Newlands' law of octaves was not widely accepted due to its lack of predictive power.
• In 1869, John Newlands arranged elements by atomic weight and noticed that every eighth element had similar properties.
• Newlands' law of octaves is considered an early form of the periodic table.
• In 1870, John Newlands proposed his law of octaves, which stated that every eighth element had similar chemical properties to the one before it.
• Mendeleev's periodic table arranged elements based on their atomic weights, with gaps left for undiscovered elements that he predicted would have certain properties.
• Mendeleev's periodic law states that when elements are arranged in order of increasing atomic mass, their properties periodically repeat themselves.
• Mendeleevs table helped predict the existence of undiscovered elements such as gallium (Ga) and germanium