1.3 Ions and the Octet Rule

What is the Octet Rule

Full valence shells have a special stability

Full or stable octet - an electron arrangement where the valence shell is filled with 8 valence electrons (exception is He=2)

When atoms combine, they tend to attain this electron arrangemet.

This is known as octet rule.

What are three ways to get this done

1. Share electrons

2. Gain electrons

3. Lose electrons

Formation of Ions

Electron Arrangement

• Netral atoms

Explain the formation of Ions that are negative, also explain the name?

Anion

Formed by the acceptance of one or more shell of a neutral atom.

Carries a negative charge.

Electron Arrangement

• Netral atoms

Explain the formation of Ions that are positive, also explain the name?

Cations

Formed by the removal of one or more electron from the valence shell of a neutral atom

Carries a positive charge

Explain Electron Arrangement Ions

Multivalent metals

Multivalent metals are metals with more than one ion charge. These elements can form different ions depending on the chemical reaction they undergo.

Explain Electron Arrangement Ions

Polyatomic ions

Polyatomic Ions are ions composed of more than one atom.

Polyatomic ions have distinct names.

1+ Charge

ammonium NH4+

3- Charge

Phosphate PO43-

Phosphite PO33-

2- Charge

Carbonate CO32-

Sulfate SO42-

Sulfite SO32-

Peroxide O22-

1- Charge

Hydrogen carbonate (bicarbonate) HCO3-

Hydroxide OH-

Nitrate NO3-

Nitrite NO2-

Chlorate ClO3-

what are they called

Common Polyatomic ions