Section 1 Development of the Modern Periodic Table The periodic table evolved over time as scientists discovered more useful ways to compare and organize the elements Section 1 Development of the Modern Periodic Table ID: 729279
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Slide1
Chapter 6The Periodic TableSlide2
Section 1Development of the Modern Periodic TableSlide3
The periodic table evolved over time as scientists discovered more useful ways to compare and organize the elements.Section 1: Development of the Modern Periodic Table
K
What I Know
W
What I Want to Find Out
L
What I LearnedSlide4
The History of the Periodic Tablehttp://www.youtube.com/watch?v=fPnwBITSmgUSlide5
In 1750, only 17 elements were known.As the rate of discovery increased, so did the need to organize the elementsIn 1789 Antoine Lavoisier grouped the known elements into metals, nonmetals, gases, and earths.Slide6
Development of the Periodic TableIn the 1700s, Lavoisier compiled a list of all the known elements of the time.
Development of the Modern Periodic TableSlide7
Development of the Periodic TableThe 1800s brought large amounts of information and scientists needed a way to organize knowledge about elements.
John Newlands proposed an arrangement where elements were ordered by increasing atomic mass.
Development of the Modern Periodic TableSlide8
Development of the Periodic TableNewlands noticed when the elements were arranged by increasing atomic mass, their properties repeated every eighth element.
Development of the Modern Periodic TableSlide9
Development of the Periodic TableMeyer and Mendeleev both demonstrated a connection between atomic mass and elemental properties.Moseley rearranged the table by increasing atomic number, and resulted in a clear periodic pattern.Periodic repetition of chemical and physical properties of the elements when they are arranged by increasing atomic number is called
periodic law
.
Development of the Modern Periodic TableSlide10
Mendeleev’s Periodic Table Medeleev made flash cards of the 63 known elements. (1863)On each card he put the name of the element, mass, and properties.When he lined the cards up in order of increasing mass, a pattern emerged.Mendeleev arranged the elements into row in order of increasing mass so that elements with similar properties were in the same column.
A deck of cards can be divided into four suits—diamonds, spades, hearts, and clubs. In one version of solitaire, a player must produce an arrangement in which each suit is ordered from ace to king. This arrangement is a model for Mendeleev's periodic table.Slide11
Periodic Table- Arrangement of elements in columns, based on a set of properties that repeat from row to row.Mendeleev’s PredictionHe could not make a complete table because many of the elements had not yet been discovered. He had to leave spaces for those elements.Eka-Aluminum – one space below Al. He predicted it would be a soft metal with a low m.p. and a density of 5.9 g/cm3The close match between Mendeleev’s prediction and the actual properties of new elements showed how useful the periodic table could be.Gallium was discovered in 1875. It’s a soft metal, m.p
. is 29.7 ˚C, and has a density of 5.91 g/cm
3
Heat from a person's hand can melt gallium. In some traffic signals, there are tiny light emitting diodes (LEDs) that contain a compound of galliumSlide12Slide13
Mendeleev’s Periodic TableHow is the table organized?Elements are arranged in order of increasing mass.What do the long dashes represent?They represent undiscovered elements.Why are masses listed with some of the dashes, but not with all of them?He was able to predict properties for some unknown elements based on the properties of neighboring elements.Slide14
Development of the Modern Periodic TableSlide15
The Modern Periodic TableThe modern periodic table contains boxes that contain the element's name, symbol, atomic number, and atomic mass.
Development of the Modern Periodic TableSlide16
The Modern Periodic TableColumns of elements are called groups.Rows of elements are called periods.Elements in groups 1,2, and 13–18 possess a wide variety of chemical and physical properties and are called the
representative elements
.
Elements in groups 3–12 are known as the
transition metals
.
Development of the Modern Periodic TableSlide17
The Modern Periodic TableElements are classified as metals, nonmetals, and metalloids.Metals are elements that are generally shiny when smooth and clean, solid at room temperature, and good conductors of heat and electricity.
Alkali metals
are all the elements in group 1 except hydrogen, and are very reactive
.
Alkaline earth metals
are in group 2, and are also highly reactive.
Development of the Modern Periodic TableSlide18
The Modern Periodic TableThe transition elements are divided into transition metals and inner transition metals.
The two sets of inner transition metals are called the
lanthanide series
and
actinide series
and are located at the bottom of the periodic table.
Development of the Modern Periodic TableSlide19
The Modern Periodic TableNonmetals are elements that are generally gases or brittle, dull-looking solids, and poor conductors of heat and electricity.Group 17 is composed of highly reactive elements called halogens
.
Group 18 gases are extremely unreactive and commonly called
noble gases
.
Metalloids
, such as silicon and germanium, have physical and chemical properties of both metals and nonmetals.
Development of the Modern Periodic TableSlide20
StaircaseLeft side is metals: Elements to the left of the semi-metal line on the periodic table are malleable (can be hammered into a shape), ductile (can be stretched into a wire) and good conductors of heat and electricity. These elements tend to lose electrons to form cations.Right side is nonmetals: Elements to the right of the semi-metal line on the periodic table (and hydrogen) are brittle and insulators of heat and electricity. These elements tend to gain electrons to form anions or share electrons as bonds to form molecules.On the steps is metaloidsSlide21Slide22
The Modern Periodic TableDevelopment of the Modern Periodic TableSlide23
"The Elements"Slide24
Essential QuestionsHow was the periodic table developed?What are the key features of the periodic table?
Development of the Modern Periodic TableSlide25
Section 2Classification of the ElementsSlide26
The PT SongSlide27
Elements are organized into different blocks in the periodic table according to their electron configurations.Section 2: Classification of the Elements
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What I Know
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What I Want to Find Out
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What I LearnedSlide28
Organizing the Elements by Electron ConfigurationRecall electrons in the highest principal energy level are called valence electrons. All group 1 elements have one valence electron.
Classification of the Elements Slide29
Organizing the Elements by Electron ConfigurationClassification of the Elements
Group 2 elements have two valence electrons. The
number of valence electrons for elements in groups 13–18 is ten less than their group number
.
The energy level of an element’s valence electrons indicates the period on the periodic table in which it is found. Slide30
The s-, p-, d-, and f-Block ElementsThe shape of the periodic table becomes clear if it is divided into blocks representing the atom’s energy sublevel being filled with valence electrons.
Classification of the Elements Slide31
The s-, p-, d-, and f-Block Elementss-block elements consist of group 1 and 2, and the element helium.Group 1 elements have a partially filled s orbital with one electron.
Group 2 elements have a completely filled s orbital with two electrons.
Classification of the Elements Slide32
The s-, p-, d-, and f-Block ElementsGroups 13–18 fill the p orbitals. In group 18, both the s and p orbitals of the period’s principal energy level are completely filled.
Classification of the Elements Slide33
The s-, p-, d-, and f-Block ElementsThe d-block contains the transition metals and is the largest block.There are exceptions, but d-block elements usually have filled outermost s orbitals, and filled or partially filled d orbitals.
The five d orbitals can hold 10 electrons, so the d-block spans ten groups on the periodic table.
Classification of the Elements Slide34
The s-, p-, d-, and f-Block ElementsThe f-block contains the inner transition metals.f-block elements have filled or partially filled outermost s orbitals and filled or partially filled 4f and 5f orbitals.
The 7f orbitals hold 14 electrons, and the inner transition metals span 14 groups.
Classification of the Elements Slide35
Alkali MetalsGroup 1AMost reactive metalsReactivity increases from the top to the bottom.So reactive many are kept under oil to prevent reacting with water or oxygen.One Valence ElectronFound in nature only in a compound.Form +1 ions because they will easily give up 1 electron for stability.http://www.youtube.com/watch?v=Ft4E1eCUItIhttp://www.youtube.com/watch?v=eCk0lYB_8c0
Element
Symbol
Hyperlink
Lithium
Li
Sodium
Na
Potassium
K
Rubidium
Rb
Cesium
Cs
Francium
FrSlide36
Alkaline Earth MetalsGroup 2AHave 2 Valence ElectronsHarder than the metals in 1A.Form +2 Ions because they easily give up 2 electrons for stability.Magnesium used in photosynthesis within the chlorophyll.Calcium used in teeth and bone.http://www.youtube.com/watch?v=B2ZPrg9IVEo
Element
Symbol
Hyperlink
Beryllium
Be
Magnesium
Mg
Calcium
Ca
Strontium
Sr
Barium
Ba
Radium
RaSlide37
Boron FamilyGroup 3AHave 3 Valence electronsForm +3 Ions because they easily give up 3 electrons for stability.1 metalloid (Boron)Six metalsAluminum is the most abundant metal in the Earth’s crust.
People are encouraged to recycle aluminum because it doesn’t take that much energy to do so.
Element
Symbol
Hyperlink
Boron
B
Aluminum
Al
Gallium
Ga
Indium
In
Thallium
Tl
Ununtrium
UutSlide38
Carbon FamilyGroup 4AHave 4 Valence ElectronsForm +/- 4 Ions because it will easily lose or gain 4 electrons for stability.1 Nonmetal (Carbon)2 Metalloids3 Metals
Metallic nature increases from top to bottom.
With the exception of water, most of the compounds in your body contain carbon.
Silicon is the second most abundant metal in the earth’s crust.
Element
Symbol
Hyperlink
Carbon
C
Silicon
Si
Germanium
Ge
Tin
Sn
Lead
Pb
Ununquadium
UuqSlide39
Nitrogen FamilyGroup 5AHave 5 Valence ElectronsForms -3 Ions because it will easily gain 3 electrons for stability.2 nonmetals2 metalloids2 MetalsNitrogen and Phosphorus are used in fertilizers.
Element
Symbol
Hyperlink
Nitrogen
N
Phosphorus
P
Arsenic
As
Antimony
Sb
Bismuth
Bi
Ununpentium
UupSlide40
Oxygen FamilyGroup 6AHave 6 Valence ElectronsForms -2 Ions because it will easily gain 2 electrons for stability.3 nonmetals2 metalloids1 metalOxygen is the most abundant element in the Earth’s Crust.
Ozone is another from of oxygen. At ground level it can irritate your eyes and lungs. At higher levels it absorbs harmful radiation from the sun.
Element
Symbol
Hyperlink
Oxygen
O
Sulfur
S
Selenium
Se
Tellurium
Te
Polonium
Po
Ununhexium
UuhSlide41
HalogensGroup 7AHave 7 Valence electronsForm -1 Ions because it will easily gain 1 electron for stability.Most reactive nonmetals increase from bottom to top.Known as “Salt Formers”5 nonmetals
1 Unknown
Fluorine is the most reactive.
React easily with most metals.
http://
www.youtube.com/watch?v=u2ogMUDBaf4
http://
www.youtube.com/watch?v=yP0U5rGWqdg
Element
Symbol
Hyperlink
Fluorine
F
Chlorine
Cl
Bromine
Br
Iodine
I
Astatine
At
Ununspetium
UusSlide42
Noble GasesGroup 8A8 Valence ElectronsHelium is the exception with only 2 valence electrons.Extremely Un-reactive (Do not form Ions)Odorless and colorless.Used in light bulbs.All are used in neon lights except argon.Have the most stable electron configuration.http://www.youtube.com/watch?v=QLrofyj6a2s
Element
Symbol
Hyperlink
Helium
He
Neon
Ne
Argon
Ar
Krypton
Kr
Xenon
Xe
Radon
Rn
Ununoctium
UuoSlide43
Classification of the Elements
Electron Configuration and the Periodic Table
EVALUATE THE ANSWER
The relationships between electron configuration and position on the periodic table have been correctly applied.
Use with Example Problem 1.
Problem
Strontium, which
is used
to produce red fireworks, has an electron configuration of [
Kr]5s
2
.
Without
using the
periodic table, determine the group, period, and block of strontium.
Response
ANALYZE THE PROBLEM
You are given the electron configuration of strontium.
KNOWN
UNKNOWN
Electron configuration = [Kr]5s
2
Group = ?
Period
= ?
Block = ?
SOLVE FOR THE UNKNOWN
For representative elements, the number of valence electrons can indicate the group number.
The s
2
indicates the strontium’s valence electrons fill the s sublevel. Thus, strontium is in group 2 of the
s-block
.
The number of the highest energy level indicates the period number.
The 5 is 5s
2
indicates that strontium is in
period 5.Slide44
Essential QuestionsWhy do elements in the same group have similar properties?
Based on their electron configurations, what are the four blocks of the periodic table?
Classification of the Elements Slide45
Section 3Periodic TrendsSlide46
Trends among elements in the periodic table include their sizes and their abilities to lose or attract electrons.Section 3: Periodic Trends
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What I Know
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What I Want to Find Out
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What I LearnedSlide47
Periodic Table Crash Coursehttp://www.youtube.com/watch?v=0RRVV4DiomgSlide48
Atomic RadiusAtomic size is a periodic trend influenced by electron configuration.For metals, atomic radius is half the distance between adjacent nuclei in a crystal of the element.
Periodic Trends Slide49
Atomic RadiusFor elements that occur as molecules, the atomic radius is half the distance between nuclei of identical atoms that are chemically bonded together.
Periodic Trends Slide50
Atomic RadiusAtomic radius generally decreases from left to right, caused by increasing positive charge in the nucleus. Valence electrons are not shielded from the increasing nuclear charge because no additional electrons come between the nucleus and the valence electrons.
Atomic radius generally increases as you move down a group.
The
outermost orbital size increases down a group, making the atom larger.
Periodic Trends Slide51
Atomic RadiusPeriodic Trends Slide52
Periodic Trends
Interpret Trends in Atomic Radii
EVALUATE THE ANSWER
The period trend in atomic radii has been correctly applied. Checking
radii values in
Figure 11
(
slide 7
) verifies
the answer.
Use with Example Problem 2.
Problem
Which has the largest atomic radius
: carbon
(C), fluorine (F), beryllium (Be), or lithium (
Li Explain
your answer in terms of trends in atomic radii.
Response
ANALYZE THE PROBLEM
You are given four elements. First, determine the groups and periods
the elements
occupy. Then apply the general trends in atomic radii to
determine which
has the largest atomic radius.
SOLVE FOR THE UNKNOWN
Determine the periods.
From the periodic table, all the elements are found to be in period 2.
Apply
the trend of
decreasing radii
across a period
.
Ordering the elements from left-to-right across the period yields: Li, Be, C, and F.
The first element in period 2, lithium, has the largest radius.Slide53
Ionic RadiusAn ion is an atom or bonded group of atoms with a positive or negative charge.When atoms lose electrons and form positively charged ions, they always become smaller for two reasons:The loss of a valence electron can leave an empty outer orbital, resulting in a smaller radius.Electrostatic repulsion decreases allowing the electrons to be pulled closer to the nucleus.
Periodic Trends Slide54
Ionic RadiusWhen atoms gain electrons, they can become larger, because the addition of an electron increases electrostatic repulsion.
Periodic Trends Slide55
Ionic RadiusPeriodic Trends
The ionic radii of positive ions generally decrease from left to right.
The ionic radii of negative ions generally decrease from left to right, beginning with group 15 or 16.
Both positive and negative ions increase in size moving down a group.Slide56
Ionic RadiusPeriodic Trends Slide57
Ionization EnergyIonization energy is defined as the energy required to remove an electron from a gaseous atom.
The energy required to remove the first electron is called the first ionization energy.
Periodic Trends Slide58
Ionization EnergyPeriodic Trends Slide59
Ionization EnergyRemoving the second electron requires more energy, and is called the second ionization energy.Each successive ionization requires more energy, but it is not a steady increase.
Periodic Trends Slide60
Ionization EnergyFirst ionization energy increases from left to right across a period.First ionization energy decreases down a group because atomic size increases and less energy is required to remove an electron farther from the nucleus.
Periodic Trends Slide61
Ionization EnergyPeriodic Trends
The ionization at which the large increase in energy occurs is related to the number of valence electrons
.
The
octet rule
states that atoms tend to gain, lose or share electrons in order to acquire a full set of eight valence electrons
.
The octet rule is useful for predicting what types of ions an element is likely to form.Slide62
ElectronegativityPeriodic Trends
The
electronegativity
of an element indicates its relative ability to attract electrons in a chemical bond
.
Electronegativity decreases down a group and increases left to right across a period.Slide63
Patterns on the Periodic TableAtomic # L to R. Atomic mass L to R. Energy level and orbitals in rows from T to B.(Physical Properties) metals metalloids nonmetals from L to R.Columns atomic mass from T to B.Columns are based on chemical properties (reactivity).Valence Electrons from L to R.Most reactive metals are on the left side.
Most reactive non-metals are on the right side.Slide64Slide65
Periodic Table Trends RapSlide66
Essential QuestionsWhat are the period and group trends of different properties?
How are period and group trends in atomic radii related to electron configuration?
Periodic Trends