Unit 3: Oxidation StatesUnit 3: Oxidation States– Oxidation State = Oxidation Number = Valence

Number -

• the charge left on an atom or ion after it has lost or

gained electrons in order to obtain a stable structure.

– the way that elements combine depends upon the

outer (valence) electrons.

– atoms or ions react in order to become stable.

– a stable arrangement generally means that the atom

or ion has an octet in their outer shell (8 electrons

with the exception of He which has 2 valence e-).

– Some elements like to lose e- to become stable like

the metals.

– Some elements like to gain e- to become stable like

the nonmetals.

– When atoms lose or gain electrons they form ions.

– Ion - a charged particle.

1) cation = (+) charged particle

2) anion = (-) charged particle

– When metals lose e- they become (+) and these (+)

ions are called cations.

– When nonmetals gain e- they become (-) and these

(-) ions are called anions.

– the charge left on the atom or ion after it reacts is

called the oxidation state.

– the oxidation state of some elements (s and p

sections of the P. Table) can be figured out, while

the other sections (d and f sections) must be

memorized.

– page 2 of your packet we will refer to often (only

includes the s and p sections.

– the most stable elements on the P. Table are the

Noble or Inert gases (Group VIIIA).

– other atoms react to get the stable arrangement of

Group VIIIA.

– For sections s and p Group # = # valence e-.

Group IA = 1 valence e-

• metals = lose e-, therefore this entire group likes

to lose 1 e- to become stable.

• when they lose 1 e- they form a +1 charge!

– 1) Nomenclature = naming

• When = only one possible (+) ox. state.

• How = element’s name ion.(ex) H 1+ = hydrogen ion

(ex) Li 1+ = lithium ion

(ex) K 1+ = potassium ion

Group IIA = 2 valence e-

• metals that have 2 e- to lose, therefore forming a

2+ ion.

(ex) Be 2+ = beryllium ion

(ex) Ca 2+ = calcium ion

(ex) Sr 2+ = strontium ion

Group IIIA = 3 valence e-

• metals that have 3 e- to lose, therefore

forming a 3+ ion.

(ex) B 3+ = boron ion

(ex) Al 3+ = aluminum ion