IIIIII III. Periodic Trends (p ) Ch. 5 - The Periodic Table

A. Periodic Law zWhen elements are arranged in order of increasing atomic #, elements with similar properties appear at regular intervals.

zAtomic Radius ysize of atom © 1998 LOGAL zFirst Ionization Energy yEnergy required to remove one e - from a neutral atom. © 1998 LOGAL zMelting/Boiling Point C. Other Properties

zAtomic Radius D. Atomic Radius Li Ar Ne K Na

zAtomic Radius yIncreases to the LEFT and DOWN D. Atomic Radius

zWhy larger going down? yHigher energy levels have larger orbitals yShielding – core (inner) e - block the attraction between the nucleus and the valence e - zWhy smaller to the right? yIncreased nuclear charge without additional shielding pulls e - in tighter D. Atomic Radius

zFirst Ionization Energy E. Ionization Energy K Na Li Ar Ne He

zFirst Ionization Energy yIncreases UP and to the RIGHT E. Ionization Energy

zWhy opposite of atomic radius? yIn small atoms, e - are close to the nucleus where the attraction is stronger zWhy small jumps within each group? yStable e - configurations don’t want to lose e - E. Ionization Energy

zSuccessive Ionization Energies yMg1st I.E.736 kJ 2nd I.E.1,445 kJ Core e - 3rd I.E.7,730 kJ yLarge jump in I.E. occurs when a CORE e - is removed. E. 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 zSuccessive Ionization Energies yLarge jump in I.E. occurs when a CORE e - is removed. E. Ionization Energy

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

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

H. Electronegativity *The measure of how strongly an atom attracts electrons when it is combined with another element Increases from left to right (except for noble gases) Increases as you move up a group

zWhich atom has the larger radius? yBeorBa yCaorBr Ba Ca Examples

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

zWhich atom has the higher melting/boiling point? yLiorC yCrorKr C Cr Examples

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