Periodic Table Flashcards
What year did John Newlands attempt to create a periodic table?
1864
How many elements were known when John Newlands created his periodic table?
63 elements
What method did Newlands use to arrange the elements?
Order of atomic weight
What phenomenon did Newlands notice while arranging the elements?
Periodicity (repeated patterns)
What problem arose from strictly following the order of atomic weight in Newlands’ table?
Some elements were in the wrong place
Who created a more advanced periodic table in 1869?
Dimitri Mendeleev
What did Mendeleev do to accommodate undiscovered elements in his periodic table?
Left gaps for their discovery
How did Mendeleev organize the elements in his table?
In vertical columns or ‘groups’ with similar properties
What did Mendeleev use his periodic table for?
To predict the existence and properties of new elements
What discovery later revealed that Mendeleev had organized elements correctly?
Discovery of subatomic particles
Mendeleev’s periodic table organized elements in order of increasing _______.
atomic number
What does atomic number represent?
Number of protons
