Polyatomic Compounds

What is a polyatomic ion? Polyatomic ions: groups of atoms that tend to stay together and carry an overall ionic charge. See pg 202

Table of Common Polyatomic Ions Name of polyatomic ion Ion fomula Ionic Charge Nitrate NO3- -1 Hydroxide OH- Bicarbonate (hydrogen carbonate) HCO3- Chlorate ClO3- Carbonate CO3-2 -2 Sulfate SO4-2 Phosphate PO4-3 -3 Ammonium NH4+ +1

Polyatomic Compound Formulas Formulas for polyatomic compounds is determined the same way as ionic compounds. Cation first, Anion second, cross over rule Al+3 + CO3-2 Al2(CO3)3

Naming Polyatomic Compounds Step 1: Write the name of the metal first. Step 2: Write the name of the polyatomic ion second. Step 3: Smile, you’re done!

Covalent Bonds

Review Ionic bond: The force of the attraction between a Positively Charged Ion and a Negatively Charged Ion

Covalent Bond Covalent Bonds: a bond formed by two or more non-metals atoms sharing one or more electrons

Differences between Ionic & Covalent bonds Ionic Bonds Covalent Bonds Bond between metals and non-metals Bond between non-metals Metal loses its valence electrons to the non-metal Atoms share their valence electrons The atoms are held together by the attraction between (+) & (-) The atoms are bonded by the shared electrons (weaker)

Molecular Compounds Molecular Compounds: a compound formed by the combination of two or more atoms held together by covalent bonds.

Covalent Bond for Chlorine

Diagrams

Naming Molecular Compounds The prefixes: Mono = 1 Di = 2 Tri = 3 Tetra = 4 Penta = 5

Naming continued To name a molecular compound: Step 1: Write how many of each atom you have. Step 2: Write the correct prefix (ex:mono,di,etc.) then the name of the element (same as on the periodic table) Step 3: Write the prefix of the next element (with –ide on the end) Note: There is no reducing!