CHEMISTRY
January 14, 2015
FINAL REVIEW
SCIENCE STARTER
• Get started on the Review.
• We will be going over the
questions
ANNOUNCEMENT
• FINAL EXAM ON JANUARY 16
AND 20
• NO HOMEWORK ACCEPTED
AFTER JANUARY 22, 2015
SECTION 1
PROPERTIES
PERIODIC TABLE
• The Periodic Table is arranged in order of
atomic number.
• Periods - the horizontal rows on the Periodic
Table
• Groups/Families - the vertical columns on the
Periodic Table
• There are only two elements that exist as
liquid – Bromine and Mercury
QUESTION 1-3
• Which element is a liquid at STP?
a)
b)
c)
d)
Bromine
Cesium
Francium
Iodine
QUESTION 2-3
• The elements on the Periodic Table are
arranged in order of increasing
– Atomic mass
– Atomic number
– First ionization energy
– Selected oxidation state
QUESTION 2-18
• The elements on the Periodic Table are
arranged in order of increasing
a)
b)
c)
d)
Atomic number
Mass number
Number of isotopes
Number of moles
QUESTION 2-24
• On the modern Periodic Table, the elements
are arranged in order of increasing
a)
b)
c)
d)
Atomic mass
Atomic number
Mass number
Oxidation number
CLASSIFICATION
• METAL
• NONMETAL
• METALLOID
METALS
• They are solid (with the exception of mercury, Hg,
a liquid).
• They are shiny, good conductors of electricity and
heat.
• They are ductile (they can be drawn into thin
wires).
• They are malleable (they can be easily hammered
into very thin sheets).
• Tend to lose electrons easily
• Reacts with oxygen
NONMETALS
•
•
•
•
•
•
•
Brittle,
Not malleable,
Not ductile,
Poor conductors of both heat and electricity,
Tend to gain electrons in chemical reactions.
Some nonmetals are liquids.
Some are allotropes
METALLOIDS
• The elements that border the stair-stepped line are
classified as metalloids.
• Have properties that are somewhat of a cross between
metals and nonmetals.
• Metalloids tend to be economically important because of
their unique conductivity properties (they only partially
conduct electricity), which make them valuable in the
semiconductor and computer chip industry.
• Some are allotropes
• List of metalloids: Boron (B), Silicon (Si), Germanium (Ge),
Arsenic (As), Antimony (Sb), Tellurium (Te), Astatine (At),
Polonium (Po)
QUESTION 1-2
• The element sulfur is classified as a
a)
b)
c)
d)
Metal
Metalloid
Nonmetal
Noble gas
QUESTION 1-4
• Which list of elements consists of a metal, a
metalloid, and a nonmetal?
a)
b)
c)
d)
Li, Na, Rb
Cr, Mo, W
Sn, Si, C
O, S, Te
QUESTION 1-6
• Which element is a metalloid?
a)
b)
c)
d)
Al
Ar
As
Au
QUESTION 1-7
• A solid element that is malleable, good
conductor of electricity, and reacts with
oxygen is classified as a
a)
b)
c)
d)
Metal
Metalloid
Noble gas
Nonmetal
QUESTION 1-8
• An element that is malleable and good
conductor of heat and electricity could have
an atomic number of
a)
b)
c)
d)
16
18
29
35
QUESTION 1-9
• Which Group 14 element is a metalloid?
a)
b)
c)
d)
Tin
Silicon
Lead
Carbon
QUESTION 1-10
• The elements in Group 2 are classified as
a)
b)
c)
d)
Metals
Metalloids
Nonmetals
Noble gases
QUESTION 1-11
• Which elements are malleable and good
conductors of electricity?
a)
b)
c)
d)
Iodine and silver
Iodine and xenon
Tin and silver
Tin and xenon
QUESTION 1-12
• Which list of elements contains a metal, a
metalloid, a nonmetal, and a noble gas?
a)
b)
c)
d)
Be, Si, Cl, Kr
C, N, Ne, Ar
K, Fe, B, F
Na, Zn, As, Sb
QUESTION 1-13
• Which Group 14 element is classified as a
metal?
a)
b)
c)
d)
Carbon
Germanium
Silicon
Tin
ALLOTROPES
• Allotropes: different forms of the same
elements
– Some elements exist in two or more forms in the
same phase
– Allotropes differ in their molecular crystal
structure and their properties
– Example: the allotropes of carbon are diamond
and graphite
QUESTION 1-1
QUESTION 3-1
• Two forms of solid carbon, diamond and
graphite, differ in their physical properties due
to the differences in their
a)
b)
c)
d)
Atomic numbers
Crystal structures
Isotopic abundances
Percent compositions
QUESTION 1-5
• At STP, solid carbon can exist as diamond and
graphite. Compared to the molecular structure
and chemical properties of diamond, graphite has
a) A different molecular structure and different
properties
b) A different molecular structure and the same
properties
c) The same molecular structure and different
properties
d) The same molecular structure and the same
properties
SECTION 2
PERIODIC TABLE TRENDS
GROUP PROPERTIES
• Elements in the same group usually share
similar chemical properties
QUESTION 2-4
• Which element has chemical properties that
are most similar to the chemical properties of
sodium?
a)
b)
c)
d)
Beryllium
Calcium
Lithium
Magnesium
QUESTION 2-11
• Which elements have the most similar
chemical properties?
a)
b)
c)
d)
Si, As, and Te
N2, O2, and F2
Mg, Sr, and Ba
Ca, Cs, and Cu
QUESTION 2-22
• Which element has chemical properties that
are most similar to the chemical properties of
fluorine?
a)
b)
c)
d)
Boron
Chlorine
Neon
Oxygen
QUESTION 3-7
• Which list includes elements with the most
similar chemical properties
a)
b)
c)
d)
Br, Ga, Hg
Cr, Pb, Xe
O, S, Se
N, O, F
GROUP NAMES
•
•
•
•
ALKALI METALS
ALKALINE EARTH METALS
HALOGEN
NOBLE GAS
ALKALI METALS
• GROUP 1
• Usually have one valence electron
• Like to give away the valence electron in a
chemical reaction
• Usually forms cations
ALKALINE EARTH METALS
• GROUP 2
• Usually have two valence electrons
• Like to give away the valence electron in a
chemical reaction
• Usually forms cations
HALOGEN
• GROUP 17
• Usually have seven valence electrons
• Like to receive the valence electron in a
chemical reaction
• Usually forms anions
NOBLE GAS
• These elements have filled valence
levels (8 valence electrons) and do
not normally react with other
substances.
QUESTION 2-5
• Which statement explains why neon is a
Group 18 element?
a) Neon is a gas at STP
b) Neon has a low melting point
c) Neon atoms have a stable valence electron
configuration
d) Neon atoms have two electrons in the first shell
ATOMIC RADIUS
• Atomic Radius - an estimate of the size of an
atom or the distance from the center of the
nucleus to the edge of the atom.
ATOMIC RADIUS - GROUP
– Atomic Radius increases from top to bottom of a
Group
• Reason: the number of energy levels increases as the
atomic number increases in a Group. As more energy
level is added, the valence electrons are further away
from the nucleus. Therefore, the atomic radius
increases as the group and energy levels increase.
ATOMIC RADIUS - PERIOD
– Atomic Radius decreases from left to right across a
Period.
• Reason: As the atomic number increases across a single
period, the electrons are being added to the same
energy level. At the same time, protons are being
added to the nucleus. The concentration of more
protons in the nucleus creates a "higher effective
nuclear charge." In other words, there is a stronger
force of attraction pulling the electrons closer to the
nucleus resulting in a smaller atomic radius.
QUESTION 2-25
• An atom of which element has the largest
atomic radius?
a)
b)
c)
d)
Fe
Mg
Si
Zn
FIRST IONIZATION ENERGY
• First Ionization Energy - the energy required to
remove the valence electron from an atom.
FIRST IONIZATION ENERGY - GROUP
– First Ionization Energy decreases from top to
bottom of a Group.
• Reason: As the atomic number increases in a Group,
the number of electron shells increases. As more
energy level is added, the valence electrons are further
away from the nucleus. Thus, the electrons are further
from the nucleus and therefore easier to remove.
More specifically, the number of electrons separating
the valence electrons from the nucleus increases
resulting in the valence electrons located in the
outermost shell to be easily removed.
FIRST IONIZATION ENERGY - PERIOD
– First Ionization Energy increases from left to right
across a period.
• Reason: As the atomic number increases a single
period, the atomic radius becomes smaller. Since the
atomic radius is smaller, the atom is smaller and the
valence electrons are positioned closer to the nucleus.
As a result, a stronger attraction exists between the
valence electrons and the nucleus. Therefore, it
becomes more difficult to remove the outermost
electron.
QUESTION 2-10
• Samples of four Group 15 elements, antimony,
arsenic, bismuth, and phosphorus, are in the
gaseous phase. An atom in the ground state of
which element requires the least amount of
energy to remove its most loosely held electron?
a)
b)
c)
d)
As
Bi
P
Sb
QUESTION 2-17
• Which atom in the ground state requires the
least amount of energy to remove its valence
electron?
a)
b)
c)
d)
Lithium atom
Potassium atom
Rubidium atom
Sodium atom
QUESITON 2-26
• Which element requires the least amount of
energy to remove the most loosely held
electron from a gaseous atom in the ground
state?
a)
b)
c)
d)
Bromine
Calcium
Sodium
Silver
ELECTRONEGATIVITY
• Electronegativity - a measure of the relative
ability of an atom to attract electrons to itself.
– Electronegativity decreases from top to bottom of a
Group.
– Electronegativity increases from left to right across a
period.
– The higher the electronegativity, the stronger the
attraction for a valence electron. In other words, the
higher the electronegativity, the more likely the atom
will steal the valence electrons. Most atoms with high
electronegativity tend to be nonmetals.
QUESTION 2-1
• Which element has atoms with the strongest
attraction for electrons in a chemical bond?
a)
b)
c)
d)
Chlorine
Nitrogen
Fluorine
Oxygen
QUESTION 2-7
• Which atom has the weakest attraction for
electrons in a chemical bond?
a)
b)
c)
d)
A boron atom
A calcium atom
A fluorine atom
A nitrogen atom
QUESTION 2-12
• In a bond between an atom of carbon and an
atom of fluorine, the fluorine atom has a
a)
b)
c)
d)
Weaker attraction for electrons
Stronger attraction for electrons
Smaller number of first-shell electrons
Larger number of first-shell electrons
QUESTION 2-15
• Which term represents the attraction one
atom has for the electrons in a bond with
another atom?
a)
b)
c)
d)
Electronegativity
Electrical conductivity
First ionization energy
Mechanical energy
QUESTION 2-13
• Which statement describes the general trends in
electronegativity and first ionization energy as
the elements in period 3 are considered in order
from Na to Cl?
a) Electronegativity increases, and first ionization
energy decreases
b) Electronegativity decreases, and first ionization
energy increases
c) Electronegativity and first ionization energy both
increase
d) Electronegativity and first ionization energy both
decrease.
QUESTION 2-16
• Which general trend is found in Period 3 as
the elements are considered in order of
increasing atomic number?
a)
b)
c)
d)
Increasing atomic radius
Increasing electronegativity
Decreasing atomic mass
Decreasing first ionization energy
QUESTION 2-27
• Which element has the lowest
electronegativity value?
a)
b)
c)
d)
F
Fr
Cl
Cr
QUESTION 2-29
• What is the most likely electronegativity value
for a metallic element?
a)
b)
c)
d)
1.3
2.7
3.4
4.0
METALLIC CHARACTERISTIC
• Metallic Characteristics – how readily an atom
loses an electron
– Metallic Characteristics increases as the atomic
number increases down a Group
– Metallic Characteristics decreases as the atomic
number increases across a Period
QUESTION 2-21
• As the elements in Period 3 are considered in
order of increasing atomic number, there is a
general decrease in
– Atomic mass
– Atomic radius
– Electronegativity
– First ionization energy
QUESTION 2-6
• Which statement describes the general trends in
electronegativity and metallic properties as the
elements in Period 2 are considered in order of
increasing atomic number?
a) Both electronegativity and metallic properties
decrease
b) Both electronegativity and metallic properties
increase
c) Electronegativity decrease and metallic properties
increase
d) Electronegativity increases and metallic properties
decrease
QUESTION 2-20
• Which general trend is found in Period 3 as
the elements are considered in order of
increasing atomic number?
a)
b)
c)
d)
Increasing atomic radius
Increasing electronegativity
Decreasing atomic mass
Decreasing first atomic energy
QUESTION 2-30
• Which characteristics both generally decrease
when the elements in Period 3 on the Periodic
Table are considered in order from left to
right?
a)
b)
c)
d)
Nonmetallic properties and atomic radius
Nonmetallic properties and ionization energy
Metallic properties and atomic radius
Metallic properties and ionization energy
VALENCE ELECTRONS
• The outermost electrons (last number in the electron
configuration) in an atom
QUESTION 2-2
• What is the total number of valence electrons
in a calcium atom in the ground state?
a)
b)
c)
d)
8
2
18
20
QUESTION 2-8
• What is the total number of valence electrons
in an atom of germanium in the ground state?
a)
b)
c)
d)
8
2
14
4
QUESTION 2-9
• In the ground state, which atom has a
completely filled valence electron shell?
a)
b)
c)
d)
C
V
Ne
Sb
QUESTION 2-14
• The elements in Group 2 have similar chemical
properties because each atom of these
elements has the same
a)
b)
c)
d)
Atomic number
Mass number
Number of electron shells
Number of valence electrons
QUESTION 2-19
• Magnesium and calcium have similar chemical
properties because a magnesium atom and a
calcium atom have the same
a)
b)
c)
d)
Atomic number
Mass number
Total number of electron shells
Total number of valence electrons
QUESTION 2-23
• An atom in the ground state has a stable
valence electron configuration. This atom
could be an atom of
a)
b)
c)
d)
Al
Cl
Na
Ne
QUESTION 2-28
• Compared to the atoms of nonmetals in
Period 3, the atoms of metals in Period 3 have
a)
b)
c)
d)
Fewer valence electrons
More valence electrons
Fewer electron shells
More electron shells
QUESTION 2-31
• An atom of argon in the ground state tends
not to bond with an atom of a different
element because the argon atom has
– More protons than neutrons
– More neutrons than protons
– A total of two valence electrons
– A total of eight valence electrons
SECTION 3
CHEMICAL BONDS
CHEMICAL BONDS
• attraction between atoms that allows the
formation of chemical substances that contain
one or more different atoms
ION
• an atom or molecule in which the total
number of electrons is not equal to the total
number of protons, giving the atom or
molecule a net positive or negative electrical
charge
CATION
• a positively charged ion
ANION
• a negatively charged ion
QUESTION 3-2
• When lithium reacts with bromine to form the
compound LiBr, each lithium atom
a) Gains one electron and becomes a negatively
charged ion
b) Gains three electrons and becomes a negatively
charged ion
c) Loses one electron and becomes a positively
charged ion
d) Loses three electrons and becomes a positively
charged ion
OCTET RULE
• atoms tend to combine to fill the outermost
electron shell resulting in 8 valence electrons
QUESTION 3-10
• Which atom attains a stable valence electron
configuration by bonding with another atom?
a)
b)
c)
d)
Neon
Radon
Helium
Hydrogen
IONIC BOND
• bond in which one or more pairs of electrons
are removed and attached to another atom,
resulting in cations and anions which attract
each other. Usually formed between a metal
and a nonmetal
QUESTION 3-3
• In the formula XF2, the element represented
by X can be classified as a
a)
b)
c)
d)
Group 1 metal
Group 2 metal
Group 1 nonmetal
Group 2 nonmetal
QUESTION 3-5
• Element X reacts with chlorine to form an
ionic compound that has the formula XCl2. To
which group on the Periodic Table could
element X belongs?
a)
b)
c)
d)
Group 1
Group 2
Group 13
Group 15
QUESTION 3-6
• The compound XCl is classified as ionic if X
represents the element
a)
b)
c)
d)
H
I
Rb
Br
COVALENT BOND
• bond in which one or more pairs of electrons
are shared by two atoms. Usually formed
between two nonmetals.
QUESTION 3-8
• What is the number of pairs of electrons that
are shared between the nitrogen atoms in a
molecule of N2?
a)
b)
c)
d)
1
2
3
6
QUESTION 3-9
• How many pairs of electrons are shared by the
two nitrogen atoms? Given the formula for
hydrazine:
a)
b)
c)
d)
1
2
3
4
ELECTRONEGATIVITY DIFFERENCE
• difference between two electronegativity
values of the atoms in the compound.
– Greater than 2.0 = ionic bond
– Less than 1.7 = covalent bond
– Between 1.7 and 2.0 = then look at classification
(metal/nonmetal) of the atom
QUESTION 3-4
• An atom of which element has the greatest
attraction for electrons in a chemical bond?
a)
b)
c)
d)
As
Ga
Ge
Se
TYPES OF COVALENT BOND
• Covalent bond may be separated into
– Polar Bond – 0.5 or greater
– Nonpolar Bond – less than 0.5
DIATOMIC ELEMENTS
• 7 diatomic atoms – hydrogen, oxygen,
nitrogen, fluorine, bromine, chlorine, iodine
• HAVE NO FEAR FOR ICE COLD BEER
ELEMENT NAME
• Capitalize first letter only
– Ex: H
– Ex: He
– Ex: Ce
– Ex: Br
QUESTION 3-11
• Which substance can be broken down by
chemical means?
a)
b)
c)
d)
CO
Ce
Ca
Cu
LEWIS ELECTRON DOT DIAGRAM
•
•
•
•
ELEMENT
IONS
IONIC BONDS
COVALENT BONDS
LEWIS - ELEMENT
LEWIS - IONS
LEWIS – IONIC BOND
Compound
KBr
CaCl2
LiF
MgI2
Lewis Dot Structure
LEWIS - COVALENT BOND