Development of Periodic Table Flashcards
1
Q
Before the 20th century how were elements arranged ?
A
1) physical and chemical properties
2) mass
2
Q
Why did scientists arrange elements in Oder if relative atomic mass ( top number)
A
Scientists didn’t know about atomic structure or electrons
3
Q
Who is Dmitri Mendeleev
A
He invented the Morden periodic table
4
Q
What did Dmitri Mendeleeve do ?
A
He arranged the elements by order of relative atomic mass but he left gaps of the properties did not match in that group
Where there were gaps he predicted new elements would be discovered and his predictions came true
