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Chemical Bonding Test Study Guide Answer key

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Chemical Bonding Test Study Guide
Salt: common name for ionic compounds
Vocabulary:
Lewis Dot Structure: Diagrams showing the
number of paired and unpaired electrons in a
compound
Alloy: A mixture of metals that acts like a
metallic bond
Anion: negatively charged particle
VSEPR: Valence Shell Electron Pair Repulsion
Model
Cation: positively charged particle
Content:
Chemical Bond: A force that holds atoms
together in a compound
Compare and contrast ionic, covalent, and
metallic bonding: Ionic-transferring electrons;
covalent-sharing electrons; metallic-bonding
with the “sea” of electrons
Conductivity: The ability to allow heat or
electricity to pass through an object
Covalent Bond: A chemical bond created by the
sharing of electrons
How can you tell from a chemical formula if a
compound is ionic or covalent? Ionics will
typically be a metal and a nonmetal; covalent
will be multiple nonmetals, only
Ductility: The ability to be drawn into wire
Electronegativity: An atom’s ability to attract
electrons
Ion: A charge particle
Ionic Bond: A chemical bond created by the
attraction between cations and anions when
electrons are exchanged
List the properties of an ionic compound (salts)
and describe how they form: They from by
transferring electrons; they have strong bonds,
crystalline structure, high melting points, are
brittle, and conduct electricity in solution
List the properties of covalent compounds
(molecules) and describe how they form: They
form from sharing electrons; they have weak
bonds, low melting points, are poor conductors
Luster: shininess
Malleability: Ability to change shape without
breaking
Metallic Bond: A chemical bond formed when
the sea of delocalized electrons
Oxidation Number: The charge an atom has
when it becomes an ion
Polar Covalent Bond: A covalent bond where
electrons are not shared equally
Polyatomic Ion: An ion containing multiple
atoms covalently bonded
List the properties of metallic bonds and
describe how they form: Form by bonding with
the “sea” of electrons around other metals;
they are lustrous, ductile, malleable, high
melting points, excellent conductors
List the 7 diatomic molecules and describe why
they are called diatomic: They are diatomic
because they cannot exist alone in nature, so
they must bond with another atom of the same
element. H2, N2, O2, F2, Cl2, Br2, I2
Describe a linear molecule and draw a picture
of one: 2 shared pairs, 0 unshared pairs
C
Describe a bent molecule and draw a picture of
one: 2 shared pairs, 2 unshared pairs
Tetrahedral, nonpolar
Chemical Formulas and Names:
Describe the process for writing a chemical
formula for an ionic bond: Find the oxidation
number for each ion involved, criss-cross the
oxidation numbers, reduce if necessary
Describe a trigonal planar molecule and draw a
picture of one: 3 shared pairs, 0 unshared pairs
What do you have to do with polyatomic ions
when writing chemical formulas? Put them in
parenthesis and do not change their subscripts
or names
What must you do to the end of an elements
name when it is the second element in a
compound? Change it to -ide
Describe a trigonal pyramidal molecule and
draw a picture of one: 3 shared pairs, 1
unshared pair
Describe a tetrahedral molecule and draw a
picture of one: 4 shared pairs, 0 unshared pairs
Draw the Lewis dot structure for the following
and determine their shapes and polarity
(Electronegativities: N = 3.0, F = 4.0, C = 2.5, Br
= 2.8)
a.) Nitrogen trifluoride
trigonal pyramidal, polar
b.) Carbon tetrabromide
Which elements require the stock system
(Roman Numerals in parenthesis) for naming
them? What does this number represent?
Transition metals, represents the oxidation
number
Which type of bond(s) require prefixes for
naming the compound? Covalent, only
Write the prefixes used for 1-10:
1- mono
2- di
3- tri
4- tetra
5- penta
6- hexa
7- hepta
8- octa
9- nona
10- deca
Determine the most likely oxidation number for
each of the following elements:
Iodine: -1
Lithium: +1
Nitrogen: -3
Sulfur: -2
Titanium (II): +2
Aluminum: +3 Barium: +2
Write the chemical formulas for the following
compounds:
a.) Magnesium chloride MgCl2
b.) Potassium dichromate K2Cr2O7
c.) Chromium (III) oxide Cr2O3
d.) dinitrogen trioxide N2O3
e.) hexaboron monosilicide B6Si
Name the following compounds:
a.)Li3N Lithium Nitride
b.)K3PO4 Potassium Phosphate
c.)NiCl3 Nickel (III) Chloride
d.)P4S5 Tetraphosphorus pentasulfide
e.) Si2Br6 Disilicon hexabromide
Explain why atoms seek out other atoms for
chemical bonding:
In order to achieve electron stability (full
valence energy level), like the noble gases
Compare and contrast single, double, and triple
bonds:
Single bonds contain one shared pair of
electrons, are weak, and are the greatest in
length
Double bonds contain 2 shared pairs of
electrons and have a strength and length
between single and triple bonds
Triple bonds contain 3 shared pairs of electrons,
are very strong, and are the shortest in length
Which of the 7 diatomic molecules contains the
strongest bonds? How do you know?
N2, because it contains triple bonds
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