SECTION 4:
VALENCE
ELECTRONS
CHAPTER 9: ELECTRONS IN ATOMS
AND THE PERIODIC TABLE
Learning Goals
•Define valence electrons, and
draw electron-dot structures
representing an atom's valence
electrons.
Valence Electrons
•Valence electrons are defined
as electrons in the atom’s
outermost orbital
•These electrons are important
because they are involved in
chemical bonding.
•Electrons not in the outermost shell
are called core electrons.
Valence Electrons
•How many valence electrons are
in the following atoms?
•He
•O
•Na
•Cl
Valence Electrons
•How many valence electrons are
in the following atoms?
•1s22s22p6
•1s22s22p63s23p64s23d104p4
•[Kr]5s24d105p2
•[Ne]3s23p3
Electron Dot Structure
•Electron-dot structure consists
of the element’s symbol
representing the nucleus,
surrounded by dots representing
the element’s valence electrons.
Electron Dot Structure
•Write the electron-dot structures
for the following elements:
•He
•O
•Na
•Cl
Electron Dot Structure
•Write the electron dot structures
for the following elements:
•1s22s22p3
•1s22s22p63s23p64s23d104p1
•[Kr]5s24d105p5
•[Ne]3s2