SECTION 4: VALENCE ELECTRONS CHAPTER 9: ELECTRONS IN ATOMS AND THE PERIODIC TABLE.

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