Download Chapter 5 Sec. 2 Sublevels and Orbitals NOTES

Chapter 5 Sec. 2 Sublevels and Orbitals NOTES

Hydrogen’s Atomic Orbitals
o Remember that Bohr’s atomic model assigned quantum numbers to electron orbits. Like
Bohr’s model, the Quantum Mechanical model assigns 4 quantum numbers to atomic
orbitals (3D region around the nucleus where electrons may exist).
o Principal Quantum Number
 Characteristics:

Trend: As n increases, the orbital gets larger, the energy of the atom increases,
and the electron spends more time farther away from the nucleus.
 An atom’s LOWEST principal energy level (ground state) is given a principle
quantum number of n=1.
o Energy Sublevels
 Each principal energy level contains energy sublevels
 Characteristics:



IMPORTANT: Each orbital can contain, at most, 2 electrons.
Question: How many sublevels would principal energy level 6 have?
Principal Energy Level 1
o Principal quantum number: n = 1
o # of sublevels: 1
 l = 0; s
 Spherical orbital
o Principal energy level 1 corresponds to a spherical orbital called the 1s orbital.



Principal Energy Level 2
o Principal quantum number: n =
o # of sublevels:
 l=
 Spherical orbital
 l=
 Dumbbell-shaped orbital
o Principal energy level 2 corresponds to the 2s and 2p orbitals.
 The 2s sublevel corresponds to the 2s orbital which is spherical like the 1s orbital,
but larger in size.
 The 2p sublevel corresponds to 3 dumbbell-shaped p orbitals designated 2px, 2py,
and 2pz.
Drawings of the 1s, 2s, 2px, 2py, and 2pz orbitals:
Principal Energy Level 3
o Principal quantum number: n =
o # of sublevels:
 l=
 Spherical orbital
 l=
 Dumbbell-shaped orbital
 l=
 “Flower”-shaped orbital
o Principal energy level 3 corresponds to the 3s, 3p, and 3d orbitals.
 The 3s sublevel corresponds to the 3s orbital which is spherical like the 2s orbital,
but larger in size.
 The 3p sublevel corresponds to 3 dumbbell-shaped p orbitals designated 3px, 3py,
and 3pz.
 The 3d sublevel corresponds to the 5 “flower”-shaped d orbitals.
 Drawings of the 5 d orbitals:

Principal Energy Level 4
o Principal quantum number: n =
o # of sublevels:
 l=
 Spherical orbital
 l=
 Dumbbell-shaped orbital
 l=
 “Flower”-shaped orbital
 l=
 Orbitals vary in shape
o Principal energy level 4 corresponds to the 4s, 4p, 4d, and 4f orbitals.
 The 4s sublevel corresponds to the 4s orbital which is spherical like the 3s orbital,
but larger in size.
 The 4p sublevel corresponds to 3 dumbbell-shaped p orbitals designated 4px, 4py,
and 4pz.
 The 4d sublevel corresponds to the 5 “flower”-shaped d orbitals.
 The 4f sublevel corresponds to the 7 f orbitals.
SUMMARY OF THE FIRST FOUR PRINCIPAL ENERGY LEVELS
Principal Quantum
Number (n)
1
Sublevels (types of
orbitals) Present
Number of Orbitals
Related to Sublevel
Total Number of Orbitals Related to
Principal Energy Level (n2)
2
3
4


Note that the number of orbitals related to each sublevel is always an ODD number.
At any given time, the electron in a hydrogen atom can occupy only one orbital. When the
hydrogen atom is in the ground state, the electron occupies the 1s orbital. Depending on the
ENERGY available the electron can move to the 2s orbital, to one of the three 2p orbitals, or to
any other vacant orbital.