Download Chemical Formulas

B-1
1
Chemical Formulas
Reviewing atoms and ions
a. A sodium ion has 11 protons and 10 electrons. What is the charge of this ion?
b. An oxygen ion has 8 protons and 10 electrons. What is the charge of this ion?
2
What is a chemical bond?
a. Magnesium atoms must lose two electrons in order to have eight valence electrons in their outermost
energy level. What is magnesium’s charge when it loses two electrons?
b. If chlorine needs only one electron to have eight valence electrons, how many chlorines are needed to
take the electrons that magnesium loses?
3
Oxidation numbers, ions, and the periodic table
There are no questions to answer in part 3.
4
Forming salts
a. A salt is any molecule made using on atom from Group 1 and one atom from Group 17. Make three
salts other than NaCl using the Periodic Table Tiles. Write their chemical formulas.
5
Predicting chemical formulas
element 1
element 2
ion 1
ion 2
number of
number of
chemical
tiles of
tiles of
formula
element 1
element 2
+
Hydrogen
Fluorine
H
F
1
1
HF
Magnesium
Sulfur
Calcium
Bromine
Aluminum
Oxygen
Potassium
Chlorine
Lithium
Argon
6
7
Nameing ionic compounds
a. Write the name of each of the compounds from part 5.
Playing molecular crosswrod
Use this table to help you work out correct molecules as you prepare for your turn
Molecule
Fe2O3
Total
Element
Oxidation Number
Element
Oxidation Number
Element
Oxidation Number
Element
Oxidation Number
Element
Oxidation Number
Element
Oxidation Number
Fe
+3
Fe
+3
O
-2
O
-2
O
-2
0
Element
Oxidation Number
Element
Oxidation Number
Element
Oxidation Number
Element
Oxidation Number
Questions
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9.
What does an atomic number tell you about an atom?
How many electrons does a neutral Einsteinium atom have?
Which element has 29 protons in its nucleus?
A neutral nitrogen atom has 7 electrons. Two of those electrons fill up the innermost energy level.
a. How many electrons does nitrogen atom have in the second energy level?
b. Is nitrogen more likely to give away the electrons in its second energy level, or to take in other electrons
in order to have a complete outer energy level?
c. What is nitrogen’s oxidation number?
Elements in column 2 of the periodic table have an oxidation number of +2. What does that tell you about
the number of electrons in their outer energy levels?
In chemistry terms, what is a salt?
Give two examples of salts.
Potassium has an oxidation number of +1. Sulfur has an oxidation number of -2. How many potassium ions
are needed to form a compound with one sulfur ion?
Why doesn’t neon usually form chemical bonds?