Names and Formulas
Transcript Names and Formulas
Today’s Do Now 10/14/2014
Draw the Lewis Structure of Chlorine.
Draw the Lewis Structure of Sodium.
If sodium and chlorine were to form a bond,
what type of bond would form? How do you
What is the definition of electronegativity?
It’s getting serious
By the end of the class period today
I will be able to…
Lewis Dot Diagrams representing
the transfer of electrons in ionic bonds.
the chemical formulas for ionic
compounds including polyatomic ions
utilizing the criss-cross method.
“-ide” means it’s just a single element
from the PT (but there can be more
than one of them)
It’s not always simple though…
Steps to Writing Ionic Formulas
1. Write positive ion first, then the negative
2. Determine the charge on each ion
3. Crisis cross and reduce
Subscripts: Numbers below the element that indicate the
number of that element.
Let’s try one together:
Write the chemical formula for Lithium Oxide.
Write the chemical formula for Magnesium Bromide.
Write the Chemical formula for Sodium Sulfide.
Write the chemical formula for Magnesium Oxide.
Sometimes there is something called a
polyatomic ion included.
What is the formula for Calcium Chlorate?
Calcium = Ca
Endings that are not “-ide”
mean you have a
A group of atoms that are bonded together and
collectively act as an anion.
Polyatomic Ions are found on the
STAAR Ref sheet:
Writing Formulas with Polyatomic Ions
Steps to writing an ionic compound:
1. Write the formulas for the ions
2. Criss cross and reduce if necessary.
3. If a subscript is written on a polyatomic ion, polyatomic
ion is placed in parentheses, and when the subscript is
one, it is not written.
Let’s do one together…
Write the formula for Calcium Nitrite.
Write the formula for Potassium Nitrate.
Write the formula for Sodium Sulfate.
Write the formula for Magnesium Phosphate.
What if there is a Transition Metal??
oxidation number of the transition
metal will be written as a roman numeral
Copper (II) chloride
Copper (III) chloride
Write the formula for…
Iron (III) Carbonate
Copper (III) sulfite
Titanium (II) oxide
Nickel (II) sulfate
Chromium (II) nitride