The document discusses the shapes and orientations of atomic orbitals. It begins by explaining that quantum numbers designate electron shells, subshells, and orbitals. It then describes the shapes of specific orbitals: s orbitals are spherical while p orbitals have three orientations and d orbitals have five orientations. The energies of orbitals in hydrogen atoms depend only on the principal quantum number with lower shells having lower energies than higher shells. The document concludes by providing video and reading preparation recommendations for the next class.

1. Shapes of
Orbitals
Dr. Narinderjit Kaur
Assistant Professor
PG Dept. of Chemistry
Kanya Maha Vidyalaya, Jalandhar

2. Quantum Numbers
A beam of atoms is split by a magnetic field.
Statistically, half of the electrons spin clockwise, the other half spin
counterclockwise.

3. Quantum Numbers
Quantum numbers designate shells, subshells, and orbitals.

4. Shapes of Orbitals
All s orbitals are spherical in shape but differ in size:
1s < 2s < 3s
2s
angular momentum
quantum number (l = 0)
ml = 0; only 1 orientation
possible
principal quantum
number (n = 2)

5. Atomic Orbitals
The p orbitals:
Three orientations:
l = 1 (as required for a p orbital)
ml = –1, 0, +1

6. x
y
z
z
xx
y
z
y
px py pz

7. The d orbitals:
Five orientations:
l = 2 (as required for a d orbital)
ml = –2, –1, 0, +1, +2
• http://mw.concord.org/modeler/showcase/simulation.html?s=http://mw2.concord.org
/public/student/quantumchemistry/atomicorbitals.html

8. Energies of Orbitals
The energies of orbitals in the hydrogen atom depend only on the principal quantum
number.
2nd shell (n = 2)
3d subshell (n = 3; l = 2)
2p subshell (n = 2; l = 1)
3rd shell (n = 3)
2s subshell
(n = 2; l = 0)
3p subshell
(n = 3; l = 1)
3s subshell
(n = 3; l = 0)

9. Prep for day 7
Must watch videos:
http://www.learnerstv.com/video/Free-video-Lecture-3349-Chemistry.htm (electron configurations)
http://www.learnerstv.com/video/Free-video-Lecture-3350-Chemistry.htm (more on electron
configurations)
http://www.learnerstv.com/video/Free-video-Lecture-3351-Chemistry.htm (more electron
configuration examples)
Other helpful videos:
http://echem1a.cchem.berkeley.edu/modules/module-3/ (UC-Berkeley watch lesson 8)
http://ocw.mit.edu/courses/chemistry/5-111-principles-of-chemical-science-fall-2008/video-lectures/
(MIT lecture 8)
Read sections 3.9-3.10
We will review for exam 1 during the next class, so practice as many example problems
from chapters 1-3 as you can before then so you can ask questions about them in the next
class period.