Download TEST REVIEW S Valence Electrons TEST REVIEW SHEET 2017

TEST REVIEW SHEET 2017
Valence Electrons
What is a valence electron?
What group are the following elements in? How many valence electrons
ectrons does
each one have?
Sr ____ ____ Kr ___ ____ Al ___ ____ Ge ___ ____ Mg _____ _____
Ca ___ ____ F____ ____ B ___ ____ O ____ ____ Ne_____ _____
Lewis Dot Diagrams
1.
2.
3.
4.
Determine the element symbol
Determine the group number and the number of valence electrons
Write the symbol
Draw the valence electrons around the symbol using dots to represent
them
Rule #1. No side can
have more than two dots
because each part of the
orvbital can only hold two
electrons.
Rule #2. When filling the
sides of the element
symbol each side gets one
dot before doubling up.
Exceptions are hydrogen
and heliem.
Draw Lewis Dot Structures for the following elements
Lithium
Nitrogen
Polonium
Chlorine
What is the octet rule for chemical bonding?
Ionic Bonds and Ionization Numbers
What types of elements bond together ionically?
What is an ion?
NOTE: If an element has <4 valence electrons it will give them away during an
ionic bond and become a positive ion. If >4, it will take them and become a
negative ion
For the most part…. metals will give away their valence electrons and nonmetals will take enough valence electrons to fill their outer shell.
Determine the charge (ionization number) for the following elements when they
form ions
Na _______ Li ______ B_______ N _______ F _________
Fill in the following ion chart using your periodic table:
Ion
Symbol
Atomic
Number
# of
# of
Protons Electrons
Name
of Ion
F-1
Ca+2
Ni+2
N-3
Use arrows to show the transfer of electrons that occurs when the
following compounds are formed. Write the correct formula for the
compound.
1. Aluminum Oxide
2. Magnesium Chloride
3. Sodium Nitride
4. Lithium Phosphide
Covalent Bonds
What types of elements bond covalently?
What happens to the valence electrons during a covalent bond?
Draw the following molecules:
a)
b)
c)
d)
e)
f)
CH4
CO2
NH3
O2
N2
H 2O
Write ionic or covalent on the line to define what type of compound forms
when the elements combine.
Ca and O _____________
N and Cl _____________ Li and P ___________
RULES FOR NAMING COVALENT COMPOUNDS
1. Prefixes are added to show the number of atoms.
mono ____di ______tri______ tetra_____ penta_____
2. There is no mono for the first element, ONLY for the second. eg. Carbon
monoxide and is not monocarbon monoxide
3. Where the suffix ends in an “a” or an “o” and the element begins with
an “a” or an “o”, the final vowel of the prefix is often dropped for ease of
pronunciation. eg. Carbon monoxide and not carbon monooxide eg.
dinitrogen tetroxide and not dinitrogen tetraoxide
Write the name of the following compounds:
1.LiF _________________________________________
2. LiCl _______________________________________
3. Li3P ______________________________________
4. BeBr2 _______________________________________
5. BeI2 ________________________________________
6. BCl3 _________________________________________
7. SiO2 __________________________________________
8. SO3 __________________________________________
9. N2O3 _________________________________________
10. Cl2O4 _________________________________________
11. CO___________________________________________
Write the molecular formula
Dinitrogen pentoxide _______________________________
Disulfur trichloride _________________________________
Tricarbon disufide _________________________________