1. How do you
Write Electron Configurations?
What is an Electron Configuration?

2. • An electron configuration is a shorthand
description of how electrons are
arranged around the nucleus of an
atom. Electron configurations are important
because they help us predict chemical
behavior. We can predict whether two
elements will react or not, and if they react,
we can also predict what kind of reaction we
are likely to have, as well as how strong the
reaction will be.

3. The Anatomy of an Atom
1. The tiny nucleus in the center of the atom
which takes up almost no space at all
2.The electron cloud which occupies all the
remaining spherical space in the atom. The
nucleus of the atom is so tiny compared to
the actual size of the atom

4. The Meaning of the Electron
Configuration
• The word "configuration" means "the
arrangement of the parts of
something." An electron
configuration describes "the arrangement of
electrons in space around a nucleus."

5. Electrons generally do not orbit the nucleus as
scientists used to think. Rather, they
hover, wiggle and jiggle, vibrate back and
forth, and move in certain patterns based
on three factors:
1. their energies
2. their orientations in space
3. their angular momentum.

7. The Electron Configuration Pattern in
the Periodic Table
• You probably already know that the elements
of the periodic table are organized by number
from 1 - 117. The number of the element,
called the atomic number, is the number of
protons found in the nucleus of exactly one
atom of that element. The atomic number is
also the number of electrons an atom has
WHEN THE ATOM IS NEUTRAL

9. It is very important to know
• at this point that some of the outer electrons
in an atom are able to jump onto or off of
other atoms according to certain physical
laws, so the number of electrons an atom has
can change from moment to moment.

10. • The protons, however, are found deep inside
the atom, in the nucleus, and CANNOT come
and go. Therefore, the number of protons in
an atom fixes the identity of the
element, regardless of the number of
electrons an atom has from one moment to
the next.

11. • As we study electron configuration (the
arrangement of electrons in atoms), we
discover a pattern. Study the periodic table
see what you can discover.

13. The standard electron
configuration pattern is as follows:

14. How to Quickly Memorize the Standard
Electron Configuration Pattern using:
(1) Look at the pattern of numbers:
• 1, 22334, 345, 456, 4567..., 56.
• If you SAY these numbers, pausing for each
comma, with a double pause before the
last "56," you will notice an easy rhythm.
Memorize this sequence.

15. • 3) Now write down the numbers first, leaving
space in between, like this:

16. • 4) Then match the letters to the numbers by
filling in the spaces leaving a little bit of space
after each letter for the superscripts (small
raised numbers).

18. s p d f
5) Finally, after each letter write the
corresponding superscript.
Each "s" gets a "2."
Each "p" gets a "6.“
Each "d" gets a "10”.
Each "f" gets a "14."

20. (2) Next, look at the pattern of letters:
• s, spsps, dps, dps, fdps..., fd.
• Again, say these letters, pausing for each
comma, with a double pause before the
last "fd." Memorize this sequence, too.