Ions and Ionic Bonding

Ions Ions are atoms or groups of atoms with electrical charges, There are positive ions or cations, these elements are commonly called metals. There are negative ions or anions, these elements are commonly called non-metals. Atoms become ions by losing or gaining electrons.

Where does the Charge Come From? Lets take Sodium…. It has 11 positive protons and 11 negative electrons. These charges cancel each other out and we say that a sodium atom is neutral. The outer shell of a sodium atom holds only 1 electron, this is not a stable arrangement. Every atom “prefers” to have a full set of electrons in its outer shell

Where does the Charge Come From? During chemical reactions, some atoms lose their outer electrons, while others gain one or more electrons to get a full set of electrons in their outer shell. Atoms with 1, 2 or 3 electrons in their outer shell tend to lose their electrons to become positive ions or cations Atoms with 5, 6 or 7 electrons in their outer shell tend to gain electrons to become negative ions or anions

Group 1 Example Sodium Atom Protons: 11+ Electrons: 11- Net Charge: 0 Loses 1 electron 11P 12N 11P 12N Sodium Atom Protons: 11+ Electrons: 11- Net Charge: 0 Sodium ion Protons: 11+ Electrons: 10- Net Charge: 1+

Group 2 Example Magnesium ion Magnesium Atom Protons: 12+ Protons: 12+ Loses 2 electrons 12P 12N 12P 12N Magnesium ion Protons: 12+ Electrons: 10- Net Charge: 2+ Magnesium Atom Protons: 12+ Electrons: 12- Net Charge: 0

Group 17 Example Fluorine Atom Protons: 9+ Electrons: 9- Net Charge: 0 Gains 1 electron 9P 10N 9P 10N Fluorine Atom Protons: 9+ Electrons: 9- Net Charge: 0 Fluorine ion Protons: 9+ Electrons: 10- Net Charge: 1-

Group 16 Example Oxygen Atom Protons: 8+ Electrons: 8- Net Charge: 0 Gains 2 electrons 8P 8N 8P 8N Oxygen Atom Protons: 8+ Electrons: 8- Net Charge: 0 Oxygen ion Protons: 8+ Electrons: 10- Net Charge: 2-

Ion Formation When non-metal atoms become negative ions, their names change. Chlorine atoms become chloride ions Bromine atoms become bromide ions Group 1 metals become +1 ions Group 2 metals become +2 ions Group 3/13 elements become +3 ions Group 7/17 elements become -1 ions Group 6/16 elements become -2 ions Group 5/15 elements become -3 ions

Transition Metals and Compound Ions Transition elements can form more than 1 type of ion. You need to learn these ones. Compound ions contain more than one type of atom chemically joined.

Table of Ions +1 Ion +2 Ion +3 Ion -3 Ion -2 Ion -1 Ion H+ Hydrogen Cu2+ Copper Fe3+ Iron (III) N3- Nitride O2- Oxide Cl- Chloride Na+ Sodium Fe2+ Iron (II) Al3+ Aluminium P3- Phosphide S2- Sulfide F- Fluoride K+ Potassium Ca2+ Calcium SO42- Sulfate I- Iodide NH4+ Ammonium Zn2+ Zinc CO32- Carbonate OH- Hydroxide Li+ Lithium Pb2+ Lead HCO3- Hydrogen Carbonate Ag+ Silver Mg2+ Magnesium NO3- Nitrate