Development of the periodic table Flashcards
How did John Dalton organise the periodic table
In order of atomic weight (NOT MASS)
How did John Newlands arrange the periodic table
In order of weight however he also noticed that every eight element seemed similar.

What was the name for John Newlands periodic table
The law of octaves
How did Mendeleev order the periodic table?
In order of atomic weight and also in periods so they could be with elements with similar properties
How did Mendeleev arrange the periodic table that John Newlands didn’t do
He left gaps for undiscovered elements which he could predict
What proved Mendeleev’s periodic table was correct?
Elements were discovered that filled the gaps and had the properties Mendeleev predicted.
Why wasn’t the order according to atomic weight always correct?
Because we didn’t know about isotopes
