1. Ion
An ion is an atom or molecule which has gained or lost electrons making it charged, either positively or negatively.
***Protons are never lost or gained they are trapped inside the nucleus.
Electrons are easer to remove or add because they are found in orbitals which are spread out around the nucleus.
Valence electrons are the ones lost or gained because they are in the last level, easy to pluck off

2. Ionize: when atom is charged
Ions that gain electrons are called ANIONS
Ions that lost electrons are called CATIONS

3. Metals lose electrons to form positive ion- cations
Nonmetals gain electrons to form negative ions - anions

4. Formation of Ions from Metals Charge on top tells you if atom gained or lost electrons
Metals lose electrons to match the number of valence electrons of their nearest noble gas
Positive ions form when the number of electrons are less than the number of protons
Group 1 metals  ion 1+
Group 2 metals  ion 2+
Group 13 metals  ion 3+

5. Formation of Sodium Ion
Sodium atom Sodium ion
Na  – e  Na +
( = Ne)
11 p p+
11 e e-

6. Formation of Magnesium Ion
Magnesium atom Magnesium ion 
Mg  – 2e  Mg2+
(=Ne)
12 p p+
12 e e-

7. Ions from Nonmetals (Anions)
In ionic compounds, nonmetals in 15, 16, and 17 gain electrons from metals (not group 18 they already have octet and are very happy)
Nonmetals add electrons to achieve the octet arrangement
Nonmetal ionic charge:
3-, 2-, or 1-

8. Fluoride Ion     1 - : F  + e : F :     2-7 2-8 (= Ne)
unpaired electron octet
   
: F  e : F :
   
(= Ne)
9 p p+
9 e e-
ionic charge

9. Ionic Bond When a chemical bond forms, energy is released.
When a chemical bond breaks energy is absorbed.
Ionic bond- electrons are completely transferred from one atom to another.
Takes place between a metal and a nonmetal
Examples; NaCl, CaCl2, K2O

10. In the process of either losing or gaining electrons between atoms, ions are formed.
These oppositely charged ions are now attracted to each other by electrostatic forces, (positive and negative attract)
This attraction is the bond.
The # of electrons lost by a metal must be equal to the # of electrons gained by non metals.
You can use as many metals and nonmetals as possible to make the transfer of electrons equal.

12. COVALENT BOND bond formed by the sharing of electrons

13. Covalent Bond
Between nonmetallic elements of similar electronegativity.
Formed by sharing electron pairs
Stable non-ionizing particles, they are not conductors at any state
Examples; O2, CO2, C2H6, H2O, SiC

14. Covalent Bonds

15. Bonds in all the polyatomic ions and diatomics are all covalent bonds

16. when electrons are shared equally
NONPOLAR COVALENT BONDS
when electrons are shared equally
H2 or Cl2

17. when electrons are shared but shared unequally
POLAR COVALENT BONDS
when electrons are shared but shared unequally
H2O

18. - water is a polar molecule because oxygen is more electronegative than hydrogen, and therefore electrons are pulled closer to oxygen.

19. METALLIC BOND bond found in metals; holds metal atoms together very strongly

20. Metallic Bond Formed between atoms of metallic elements
Electron cloud around atoms
Good conductors at all states, lustrous, very high melting points
Examples; Na, Fe, Al, Au, Co

21. Ionic Bond, A Sea of Electrons