Finding the Number of Valence Electrons for an Element

Wayne Breslyn
Wayne Breslyn
1.1 میلیون بار بازدید - 11 سال پیش - An explanation and practice for
An explanation and practice for finding the number of valence electrons for elements on the periodic table.  This is a key first step for drawing Lewis dot structures for molecules.

Looking at the Periodic Table, atoms have a regularly occurring number of valence electrons based on their Group number.  

Group 1: One Valence Electron
Group 2: Two Valence Electrons
Group 13 (also called 3A): Three Valence Electrons
Group 14 (also called 4A): Four Valence Electrons
Group 15 (also called 5A): Five Valence Electrons
Group 16 (also called 6A): Six Valence Electrons
Group 17 (also called 7A): Seven Valence Electrons
Group 18 (also called 8A): Eight Valence Electrons*

* Although in Group 18, the element Helium only has two valence electrons.

In general we do not draw Lewis Structures for atoms of the Transition Metals (Groups 3-12).

Get more chemistry help at www.Breslyn.org.
11 سال پیش در تاریخ 1392/03/05 منتشر شده است.
1,111,745 بـار بازدید شده
... بیشتر