Development of periodic table Flashcards
1
Q
Before the discovery of protons, electrons and neutrons, what did scientists order elements by?
A
Their atomic weights
2
Q
How did Mendeleev reorder the periodic table?
A
By grouping elements with similar properties so patterns could be seen. This meant he sometimes left gaps or changed the order of atomic weight
3
Q
Elements with properties Mendeleev predicted were ______________________________
A
Discovered and filled the gaps
4
Q
How are the elements on the modern periodic table arranged?
A
In order of increasing atomic number
5
Q
What are the columns called?
A
Groups (going down) on the periodic table
6
Q
How does the number of elctrons in the outermost shell relate to the periodic table?
A
It’s the same as its group on the periodic table.
