QUANTUM
NUMBERS
~
describe one specific electron
~
1st quantum number = PRINCIPAL QUANTUM NUMBER
~ abbreviated
"n"
~ tells the
energy level the electron is located in
~ n = number of
the energy level
~ 1st energy
level: n = 1, 4th energy level: n = 4, etc.
~ 2nd quantum number
= ANGULAR MOMENTUM QUANTUM NUMBER
~
abbreviated " l "
~ tells the sublevel the
electron is located in
~ tells shape of orbital
~ "s" sublevel: l = 0, "p"
sublevel: l = 1, "d"
sublevel: l = 2, "f"
sublevel: l = 3
~
3rd quantum number = MAGNETIC QUANTUM NUMBER
~ abbreviated "m"
~ tells which orbital the
electron is in
~ tells orientation of orbital
around nucleus
~ m = - l .. + l
~ 4th quantum number = SPIN QUANTUM
NUMBER
~ abbreviated " s "
~ tells which electron is
being described
~ tells which way electron is
spinning
~ s = -1/2
or +1/2
Pauli Exclusion Principle:
EXAMPLE QUESTIONS:
1.) What are the 4 quantum numbers for
the following electron?
h
3 p
2.) If the electron in question 1 was the last
electron added, what element would it be?
3.) Draw in the electron (and the orbital
notation) for the electron with the following quantum numbers.
n
= 3 l = 2 m = -1 s = - ½
4.) How many electrons in an atom can have the
quantum numbers n = 3 and l = 1?
5.) What are the four quantum numbers
for the electron circled in the diagram below?
n
= l
= m = s =
