Post on 03-Jan-2016
Chp 4-1Chp 4-1Periodic LawPeriodic Law
Periodic law - periodic Periodic law - periodic table is organized based table is organized based on the on the atomic #atomic #, chemical , chemical & physical properties of & physical properties of the elementsthe elements
Mendeleev is the creator Mendeleev is the creator of the periodic table used of the periodic table used atomic massatomic mass
The Periodic TableThe Periodic Table
GroupGroup A vertical columnsA vertical columns Elements in a group share the same chemical Elements in a group share the same chemical
propertiesproperties
PeriodPeriod A horizontal rows A horizontal rows Elements in the same period have the same Elements in the same period have the same
number of energy levelsnumber of energy levels
The Periodic TableThe Periodic Table Elements’ chemical properties are Elements’ chemical properties are
determined by the number of valence determined by the number of valence electrons electrons
Valence electrons Valence electrons are electrons that are in are electrons that are in the outermost energy level of an atom (in the the outermost energy level of an atom (in the S and P orbital)S and P orbital)
Metals PropertiesMetals Properties
Most elements are metalsMost elements are metals They are good conductors of electricityThey are good conductors of electricity Most are ductile (can be rolled into wire) Most are ductile (can be rolled into wire)
and malleable (can be hammered or rolled and malleable (can be hammered or rolled into sheets)into sheets)
Can form Can form alloys alloys - solid or liquid mixtures - solid or liquid mixtures of metalsof metals
Check-InCheck-In
A = metalsA = metals
B = non metalsB = non metals
C = metalloidsC = metalloids
Classify the following elements: Classify the following elements: 1.Na 1.Na 2.H 2.H 3.C 3.C 4.Ca 4.Ca
5.Si 5.Si 6.W6.W
Alkali MetalsAlkali Metals
Group 1Group 1 Highly reactive (easily combine with other Highly reactive (easily combine with other
elements)elements) React with water to make alkaline (basic) React with water to make alkaline (basic)
solutionssolutions Will give away 1 valence electronWill give away 1 valence electron Found in nature as compoundsFound in nature as compounds
Alkaline Earth MetalsAlkaline Earth Metals Group 2Group 2 22ndnd most reactive group most reactive group Found in nature in Found in nature in
compoundscompounds Give away 2 v.e. Give away 2 v.e.
Transition MetalsTransition Metals d d and and f f blocksblocks Most lanthanides and Most lanthanides and
actinides (f-block) are actinides (f-block) are radioactive.radioactive.
Generally less reactive Generally less reactive than alkali and alkaline than alkali and alkaline earth metalsearth metals
HalogensHalogens
Group 17Group 17 Gain 1 electron in reactions Gain 1 electron in reactions React with metals to form saltsReact with metals to form salts Halogens are non-metalsHalogens are non-metals Seven valence electrons making them Seven valence electrons making them
highly reactivehighly reactive
Noble GasesNoble Gases
Group 18Group 18 Not reactive at allNot reactive at all Eight valence electrons makes them very Eight valence electrons makes them very
stable (outermost energy level is full)stable (outermost energy level is full) Also called inert gases because of their Also called inert gases because of their
low reactivitylow reactivity
HydrogenHydrogen
Most common element in the universeMost common element in the universe Found in many organic compoundsFound in many organic compounds
Chp 4-3Chp 4-3Periodic TrendsPeriodic Trends
Atomic radiusAtomic radius Ionization energyIonization energy ElectronegativityElectronegativity Electron affinityElectron affinity
Periodic TrendsPeriodic Trends Atomic Radius: Atomic Radius: The estimated distance The estimated distance
from the nucleus to the outer most from the nucleus to the outer most electronselectrons
IncreasesIncreases down a groupdown a group As electrons energy levels are added, the As electrons energy levels are added, the
nucleus becomes largernucleus becomes larger DecreasesDecreases across a period across a period # protons increases which pulled the v.e. # protons increases which pulled the v.e.
closer to the nucleus closer to the nucleus
Periodic TrendsPeriodic Trends Ionization Energy Ionization Energy - - The energy The energy required to required to
remove one electron from an atom or ionremove one electron from an atom or ion DecreasesDecreases down a group down a group Electrons are farther from the nucleus and Electrons are farther from the nucleus and
easier to removeeasier to remove IncreasesIncreases across a period across a period Electrons are closer to the nucleusElectrons are closer to the nucleus
Periodic TrendsPeriodic Trends ElectronegativityElectronegativity - - the ability the ability of an atom to of an atom to
attract electrons to itselfattract electrons to itself Decreases Decreases down a groupdown a group Increases Increases across a periodacross a period
Periodic TrendsPeriodic Trends
Electron Affinity - Electron Affinity - the energy change that the energy change that occurs when an electron is added to a occurs when an electron is added to a neutral atomneutral atom Decreases Decreases down a group down a group Increases Increases across a periodacross a period
ExampleExample
Consider the following elements: Na, Al, P, Cl
Largest and smallest radius? Highest electronegavity?
Fill in your periodic table Color and label each
of these: Main-group metals Transition metals Lanthanides and
Actinides Nonmetals Noble Gases Metalloids
Label with arrows each of these trends: Atomic Radius Ionization energy Electronegativity Electron affinity Reactivity (this is
different on each side of the PT)