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Chemistry Chapter Chemistry Chapter 5&65&6
The Periodic Law Notes The Periodic Law Notes 55
Mendeleev’s Periodic Table
Dmitri Mendeleev
Modern Russian Table
Chinese Periodic Table
Stowe Periodic Table
A Spiral Periodic Spiral Periodic TableTable
Triangular Periodic Table
““Mayan” Mayan”
Periodic Periodic TableTable
Orbital filling table
Periodic Table with Group Names
Easily lose valence electron (Reducing agents)
React violently with water Large hydration energy React with halogens to form
salts
The Properties of a Group: the Alkali Metals
Sublevel Blocks of the Periodic TableSublevel Blocks of the Periodic Table
Figure 5-5 p. 129
ss-block-block• Group 1Group 1• Alkali MetalsAlkali Metals
– nnss11 is highest level is highest level
– Silvery appearanceSilvery appearance
– Soft—cut with knifeSoft—cut with knife
– Highly reactive—never Highly reactive—never found free in naturefound free in nature
– Low melting points Low melting points <100<100ooCC
• Group 2Group 2• Alkaline-earth metalsAlkaline-earth metals
– nnss22 is highest level is highest level
– Harder & denser, w/ Harder & denser, w/ higher melting points higher melting points than Group 1than Group 1
– Highly reactive—never Highly reactive—never found free in naturefound free in nature
Special exceptions to Special exceptions to ss-block-block• HydrogenHydrogen
– Has nHas nss11
– Totally different Totally different properties from alkali properties from alkali metalsmetals
• HeliumHelium– Has nHas nss22
– Highest level is Highest level is completely fullcompletely full
– Stable like noble gasesStable like noble gases
dd-block-block• dd sublevel for preceding energy level is filling sublevel for preceding energy level is filling• dd sublevel filling has some deviations—Group 11: sublevel filling has some deviations—Group 11:
Cu, Ag, Au Cu, Ag, Au – Outer Outer ss & & dd sublevels still have same # e sublevels still have same # e--
• Transition elements: d-block metals w/ typical Transition elements: d-block metals w/ typical metallic propertiesmetallic properties– Less reactive than Group 1 & 2Less reactive than Group 1 & 2
– Exist free in natureExist free in nature
– Good conductors of electricityGood conductors of electricity
– High luster (shiny)High luster (shiny)
pp-block-block• All elements of Groups 13-18 except HeliumAll elements of Groups 13-18 except Helium• Properties vary greatlyProperties vary greatly• Nonmetals (right hand end)Nonmetals (right hand end)• All six metalloidsAll six metalloids
– Brittle solidsBrittle solids– Some properties of metals and nonmetalsSome properties of metals and nonmetals
• Eight metals (left hand side and bottom of the block)Eight metals (left hand side and bottom of the block)– Harder and denser then s-block alkaline-earth metalsHarder and denser then s-block alkaline-earth metals– Softer and less dense than d-block metalsSofter and less dense than d-block metals– Stable in the presence of airStable in the presence of air
• Group 17 HalogensGroup 17 Halogens– Most reative of the nonmetalMost reative of the nonmetal– 7 electrons in outer shell7 electrons in outer shell
ff-block-block• Lanthanides & ActinidesLanthanides & Actinides• 14 elements—seven 414 elements—seven 4ff orbitals are filling orbitals are filling• LanthanidesLanthanides
– Similar reactivity to Group 2Similar reactivity to Group 2– Shiny metalsShiny metals
• ActinidesActinides– Only 1Only 1stst four found in nature four found in nature– All are radioactiveAll are radioactive
Half of the distance between nucli in covalently bonded diatomic molecule
"covalent atomic radii"
Periodic Trends in Atomic Radius
Radius decreases across a period Increased effective nuclear charge dueto decreased shielding
Radius increases down a group Addition of principal quantum levels
Determination of Atomic Radius:
Table of Table of Atomic Atomic
RadiiRadii
Increases for successive electrons taken from the same atom
Tends to increase across a period
Electrons in the same quantum level do not shield as effectively as electrons in inner levels
Irregularities at half filled and filled sublevels due to extra repulsion of electrons paired in orbitals, making them easier to remove
Tends to decrease down a groupOuter electrons are farther from thenucleus
Ionization Energy - the energy required to remove an
electron from an atom
Ionization of Magnesium Mg + 738 kJ Mg+ + e-
Mg+ + 1451 kJ Mg2+ + e-
Mg2+ + 7733 kJ Mg3+ + e-
Table of 1st Ionization Energies
Another Way to Look at Ionization Energy
Affinity tends to increase across a period
Affinity tends to decrease as you go down in a Group or family
Electrons farther from the nucleusexperience less nuclear attraction
Some irregularities due to repulsive forces in the relatively small p orbitals
Electron Affinity - the energy change associated with the addition of an electron
Table of Electron AffinitiesTable of Electron Affinities
Ionic RadiiIonic RadiiCations
Positively charged ions Smaller than the
corresponding atomAnions
Negatively charged ions Larger than the corresponding atom
Summation of Periodic Trends
Table of Ion Sizes
ElectronegativityElectronegativity
A measure of the ability of an atom in a chemicalcompound to attract electrons
Electronegativities tend to increase across a period
Electronegativities tend to decrease down a group or remain the same
Periodic Table of Electronegativities