IPC Notes Stability in Bonding & Electron Dot Diagrams

Chemical Stability Atoms combine in order to become chemically stable. A chemically stable atom has a full outer shell of electrons.

Chemical Stability Atoms combine by gaining, losing or sharing electrons. A chemical bond is the force that holds atoms together in a substance.

Chemical Stability All elements combine except for the noble gases (group VIII A). Why? The noble gases are the only elements that already have a full outer shell of electrons.

Chemical Stability A compound consists of 2 or more elements chemically combined. A chemical formula shows the elements that a compound contains and the number of atoms of each element.

Chemical Stability A subscript shows the number of atoms of an element in a compound. ex) H 2 O

Chemical Stability Valence electrons are the electrons in the outer energy level of an atom. Valence electrons are responsible for chemical bonding.

Chemical Stability An elements number of valence electrons is the same as the group number. This is why elements in the same group are chemically similar.

Oxidation Numbers An elements oxidation number is the charge that an atom has after gaining or losing electrons to become stable. The oxidation number is determined by the group number.

Oxidation Numbers The metals on the left side of the periodic table will lose electrons to have a positive oxidation number. The nonmetals on the right side of the periodic table will gain electrons to have a negative oxidation number.

Memorize the Charges!

Electron Dot Diagrams An electron dot diagram shows the valence electrons for an atom. First, write the symbol for the element.

Drawing Dot Diagrams Then, put a dot to show each electron in the outer shell, in the following order: X

The reason for this order is complex and will be covered when you take Chemistry. Drawing Dot Diagrams

boron

neon

nitrogen

phosphorus

sodium

chlorine