The Periodic Table and the Atom - Development of the Periodic Table

Question 1

Before the discovery of sub-atomic particles how did scientists attempt to classify elements

Answer 1

in order of their atomic weights

Question 2

what was wrong with the early periodic tables

Answer 2

The early periodic tables were incomplete and some elements were placed in inappropriate groups if the strict atomic weight order was followed

Question 3

how did mendeleev overcome the issues the early periodic table faced

Answer 3

he left gaps for elements he thought had not yet been discovered and in some places changed the order

Question 4

what happened after mendeleev’s predictions

Answer 4

Elements with properties predicted by mendeleev were discovered and filled the gaps