Writing Chemical Formulas
Elements are represented by ____________________________. Ex:
Compounds are represented by _________________________. Ex:
2 or more elements combine to form a ________________________. Ex:
Formula shows 2 things:
1.
2.
NaCl
AlPO4
When only one atom of an element is present, no number is used. We don’t write ___’s.
If more than one atom of an element is present, we state how many by using a ___________________.
How many atoms are present in:
1. CuSO4
2. HF
3. NH4Cl
4. Mg(NO3)2
*There are 2 nitrate ions. Remember with polyatomic ions everything ______________________ the parenthesis must
be ______________________ by the # _____________________________ the parenthesis.
Atoms/Electrons
All atoms want _____ electrons in their outer shells. These are called __________________ __________________
They are willing to ________________ or _______________ electrons to achieve this # (Octet Rule)
Ions
•
An ion is an atom or group of atoms that has a ____________________
•
A compound that is composed of ions is called an ________________ _________________________.
•
Ionic compounds usually form between a ________ (cation) and a ____________ (anion). (Look at PTable)
•
They may also form between a ________________ ____ (like ammonium) and either a metal or nonmetal.
•
In ionic compounds, you will ________________________ valence electrons
Cation (Metal)
Anion (Nonmetal)
Monatomic ions:
Polyatomic ions:
Write charges on Periodic Table
Opposite charges ______________________
Even though ions have charges, cations and anions must combine in a way that __________ out their __ and __charges.
Rules for Writing Ionic Compounds (Metal & NonMetal)
1.
2.
-
-
3.
4.
5.
*
*
Write the Formula
1. Sodium chloride
2. Iron (III) bromide
3. Calcium sulfide
4. Lithium nitrite
5. Ammonium sulfate
Rules for Naming Ionic Compounds (Regular & Polyatomic)
1.
2.
Name the Formula
1. NaCl
2. MgSO4
3. K3PO4
4. Ca(ClO3)2
5. NH4NO2
Rules for Naming Ionic Compounds (Variable Charge)
1.
2.
3.
4.
5.
6.
-
Name the Formula
1. PbO2
2. FeSO4
3. CoCl2
4. Cu3(PO4)2
5. ZnCl2
Molecule:
Diatomic Molecule:
Magnificent 7 Examples:
They never exist ______________________
Covalent Compounds are between 2 __________________________
Prefixes
Rules for Writing Covalent Compounds
1.
2.
3.
4.
*
*
*
Write the Formula
1. Carbon dioxide
2. Phosphorus trifluoride
3. Nitrogen bromide
4. Hexaselenide pentaiodide
5. Dicarbon monosulfide
Rules for Naming Covalent Compounds
1.
2.
3.
4.
*
*
Name the Formula
1. SO2
2. N2F5
3. CO
4. S3Cl4
5. FI3
Hydrates
Some compounds trap ___________________crystals when they form. These are hydrates.
Both the name and the formula needs to indicate how many water molecules are trapped.
In the name we add the word ___________________ with a prefix that tells us how many _________ molecules.
In the formula you put a _____ then write the prefix for the __________ of molecules
Ex: Calcium Chloride Dihydrate
Ex: Chromium (III) Nitrate Hexahydrate
Naming Acids – LOOK @ CRM
If ends in “ide” 
If ends in “ate” 
If ends in “ite” 
Examples:
1. HCl
2. H2S
3. HNO3
4. HNO2
5. H3PO3
Writing Acids
Find out what elements are in it and then LOOK @ CHARGES & BRING THEM DOWN
Examples:
1. Hydrochloric Acid
2. Sulfuric Acid
3. Carbonic Acid
4. Phosphoric Acid
5. Nitric Acid
Mix Examples: