Development of Periodic Table

• What order was the periodic table originally done by?

  Originally ordered by Atomic Weights as proton and electron weren’t discovered but not every element fit and was also incomplete
• What did Mendeleev do?

  Switched some elements and ordered by increasing atomic weight but also decided based on chemical properties.Left gaps as he believed some elements were still undiscovered and made predictions 
• Why was Mendeleev's table accepted later on?

  Later was accepted as he left gaps showing that he knew other elements were not there and his predictions were true