IIIIII Periodic Trends The Periodic Table

1.Atomic Radius y½ the distance between two identical atoms bonded together © 1998 LOGAL 2.Ionization Energy yEnergy required to remove one e- from a neutral atom. © 1998 LOGAL Periodic Properties

3.Electron Affinity yAttraction for additional electrons Periodic Properties 4.Electronegativity y“ Pull” an atom has on electrons when bonded to another atom

zAtomic Radius 1.Increases to the LEFT and DOWN A. Atomic Radius

2.Why larger going down? a)Adding energy levels b)Shielding - core e - block the attraction between the nucleus and the valence e - A. Atomic Radius

3.Why smaller to the right? a)Increased nuclear charge (i.e. more protons in nucleus) without more shielding pulls e - in tighter A. Atomic Radius

11 p+ Na 17 p+ Cl Nucleus not strong enough to pull valence e- in tight Stronger nucleus pulls valence e- in tight

zAtomic Radius A. Atomic Radius Li Ar Ne K Na

zIonic Radius yCations (+) xlose e - xsmaller © 2002 Prentice-Hall, Inc. yAnions (–) xgain e - xlarger B. Ionic Radius

zIonic Radius y“Tug of War” between positive nucleus and negative electrons. yCations: nucleus is “stronger” yAnions: electrons are “stronger” B. Ionic Radius

zWhich atom has the larger radius? yBe orBa yCa orBr Ba Ca Examples

zWhich particle has the larger radius? ySorS 2- yAlorAl 3+ S 2- Al Examples

zFirst Ionization Energy – energy needed to remove ONE electron. C. Ionization Energy K Na Li Ar Ne He

zFirst Ionization Energy 1.Increases UP and to the RIGHT C. Ionization Energy

2.Why opposite of atomic radius? a)In small atoms, e - are close to the nucleus where the attraction is stronger; it takes a lot of energy to strip an e - away! 3.Why small jumps within each group? a)Stable e - configurations don’t want to lose e - C. Ionization Energy

yMg1st I.E.736 kJ 2nd I.E.1,445 kJ Core e - 3rd I.E.7,730 kJ 4.Successive Ionization Energies a)Large jump in I.E. occurs when a CORE e - is removed after all valence e - have been removed. C. Ionization Energy

yAl1st I.E.577 kJ 2nd I.E.1,815 kJ 3rd I.E.2,740 kJ Core e - 4th I.E.11,600 kJ 4.Successive Ionization Energies a)Large jump in I.E. occurs when a CORE e - is removed after all valence e - have been removed. C. Ionization Energy

zWhich atom has the higher 1st I.E.? yNorBi yBa orNe N Ne Examples

D. Electron Affinity zElectron Affinity 1.Increases UP and to the RIGHT

D. Electron Affinity 2.Why smaller going down? a)e - further from the nucleus b)Greater shielding; additional e - feel the attraction from the nucleus less. 3.Why greater to the right? a)Higher nuclear charge without greater shielding; stronger nucleus has a greater attraction for e - (atoms tend to make anions)

zWhich atom has the higher e - affinity? yK orBr yForI Br F Examples

E. Electronegativity zElectronegativity 1.Increases UP and to the RIGHT F

zIf the following atoms were bonded together, which would have the higher electronegativity? yP or S ySe or O SOSO Examples

zMelting/Boiling Point yHighest in the middle of a period. F. Melting/Boiling Point