His. of periodic table Flashcards
WHO attributed to the idea of arranging the known elements of his time in a table according to their chemical and physical prop.
Dmitri Mendeleev
Mendeleev predicted that the empty spaces on his periodic table represented:
undiscovered elements
WHO arranged the periodic table of elements in the order of atomic #
Henry Moseley
What did Moseley’s change solve
the tellurium/iodine problem + creation of modern table
The Periodic Law:
states that the physical/ chemical properties of the elements are periodic functions of their atomic #’s
How many periodic groups?
18
Periodic Groups:
elements of the same group have the
same valence configuration,
valence electrons, and
similar chemical properties
Why do elements in the same group have similar properties?
have same # of valence electrons so lose/gain same # of e- when forming ions
How many periodic periods?
7
Periodic Periods:
elements of the same period have same # of occupied energy levels
All elements in same period have the same:
of principle energy levels (PEL)
Valence Electrons:
electrons found in the outermost energy level of atoms
of valence e- in MAIN GROUP ELEMENTS is = to
its group # minus 10
