M2L4a.txt

#
# File:   content-mit-8-421-2x-subtitles/M2L4a.txt
#
# Captions for 8.421x module
#
# This file has 25 caption lines.
#
# Do not add or delete any lines.
#
#----------------------------------------

So our big next chapter is now atoms or atomic structure.
And we build it up in several stages.
Well, first things first.
And the first things are the big chunks of energy
which define the electronic structure.
We discuss electronic structure for one electron and two
electron atoms, hydrogen and helium.
We don't go higher in the periodic table.
But then we talk about other contributions
to the energy of atoms, other contributions to the level
structure of atoms.
And this will start with fine structure, the lamb shift.
We bring in properties of the nucleus
by discussing hyperfine structure.
And then, as the next big chapter,
we will learn how external fields, magnetic fields,
electric fields, and electromagnetic fields
will modify the level structure of atoms.
So by going through all those differently layers,
we will arrive at a rather complete description.
If you have an atom in the laboratory,
what determines its energy level and the transitions
between those energy levels?
So this is our agenda for the next few lectures.