Name:
Period:
REVIEW PACKET
Remember, in order to do well in chemistry, you must be able to recall prior information you’ve
learned. This packet will go through what I believe to be some of the most essential topics that we’ve
covered. This will allow you to get a preview on the concept of the bonding! Let’s begin…
1. Determining the number of valence electrons
When will I use this??
-drawing electron dot diagrams
-drawing lewis structures
Valence electrons are __________ shell electrons. They are important because atoms react to have
eight valence electrons (also known as an _________). Valence electrons have a large impact on the
reactivity of atoms.
So, how can we tell the number of valence electrons for main group elements?
We simply count across!
How many valence electrons do the following elements contain? Write the number on the line to the
right of the element.
Carbon _____ Fluorine _____ Phosphorus _____ Chlorine ____ Sodium _____
Potassium ____ Sulfur _____ Neon ____ Boron ____ Bromine ____ Nitrogen _____
2. Determining the charge on an atom (note **many of you are mixing up valence electrons and
charge)
When will we use this?
-writing formulas
Atoms have charge when they gain or lose ___________. In other words, they become an ion. We
will be doing reactions with many ionic compounds. In a few weeks we will be writing balanced
equations using charges to write formulas.
This also is a trend across the table similar to valence electrons. It is actually a result of the number
of valence electrons. Remember atoms want 8 valence electrons.
Oxygen- 6 valence electrons
Needs two more electrons
Gain 2 electrons = -2 charge (electrons are negative when we gain them we become_________)
Lithium- 1 valence electron
Needs to lose 1 electron to have inner shell of 8 become outer shell
Lose one electron= +1 charge (electrons are negative when we lose them we become __________)
What is the charge of the following atoms? Write the charge on the line to the right.
Magnesium ____ Iodine ____ Aluminum ____ Argon ____ Potassium ____
Nitrogen ___ Sulfur ____ Chlorine___ Sodium ____ Hydrogen ___ Calcium _____
For atoms that make multiple charges their charge is told by the roman numeral to the right of their
name. Ex: copper (II) chloride, the charge on copper (Cu) is 2+
Give the charge for the following metals.
Lead (IV) oxide; Lead ___
Chromium (II) iodide; Chromium ___
Iron (III) nitride; Iron ___
3. Determining whether a compound is ionic or covalent
When will I use this??
-naming compounds
-writing formulas
-understanding properties
The easiest way to identify the bond is to see what makes up the compound.
Ex: 𝑵𝒂𝟐 𝑶: Na (sodium)- metal, O (oxygen)- nonmetal : ionic compound
Ex: 𝑷𝑪𝒍𝟓 : P (phosphorus)- nonmetal, Cl (chlorine) nonmetal : covalent compound
Determine whether the compound is ionic or covalent. Write the bond type (ionic or covalent) on
the line to the right.
calcium nitride: ________
trisulfur pentoxide: ________
potassium chloride: _________
aluminum oxide:__________
carbon monoxide: ___________
lead (III) iodide: ____________
phosphorus tetrabromide: ________
𝑵𝟑 𝑭𝟔 : _______________
𝑲𝑩𝒓 : ________________
𝑵𝒂𝟐 𝑺 : ________________
𝑵𝑶 : ___________________
𝑴𝒈𝑪𝒍𝟐 : _________________
𝑨𝒓𝑭𝟓 : ______________
𝑵𝟒 𝑰𝟗 : ____________________
4. Writing formulas from names
When will I use this??
-all the time for the rest of the semester and your life
First, determine if the compound is ionic or covalent as we did above.
If ionic, you need to determine the charges (hey we did that in #2!). Then you simply do the crisscross applesauce (arrow) method. Remember subscript will never be positive or negative.
Ex: aluminum oxide
𝑨𝒍𝟐 𝑶𝟑
If covalent, you use the prefixes in the name to create the subscript.
Ex: tetrasulfur heptaoxide
𝑺𝟒 𝑶𝟕
Ex: carbon monoxide
𝑪𝑶
Write the formula for the following compounds.
Name
Bond
Potassium
oxide
Nitrogen
tetrachloride
Iron (II) sulfide
Calcium
fluoride
Dicarbon
octaphosphide
Formula
Name
Aluminum
oxide
Carbon
tetrachloride
Copper (I)
nitride
Trisulfur
nonaiodide
Sodium
bromide
Bond
Formula