Periodic Table Trends

Remember these groups of the periodic table?

Organization by atomic # = repeating patterns in chem and physical behavior

He 2 Ne 10 Ar 18 Kr 36 Xe 54 Rn 86 1s21s2 1s 2 2s 2 2p 6 1s 2 2s 2 2p 6 3s 2 3p 6 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 6s 2 4f 14 5d 10 6p 6 How the configurations of the noble gases similar? The outer energy level is completely full!

1s11s1 1s 2 2s 1 1s 2 2s 2 2p 6 3s 1 1s 2 2s 2 2p 6 3s 2 3p 6 4s 1 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 1 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 6s 1 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 6 6s 2 4f 14 5d 10 6p 6 7s 1 H 1 Li 3 Na 11 K 19 Rb 37 Cs 55 Fr 87 How are the configurations of the alkali metals similar? They all end in s 1

patterns in e - config = patterns in properties= Periodic Trends.

Rings/orbits/ shells: “how far out the e - cloud spans” More E levels= valence e - further away from nucleus

1. Ca or Ge 2. Al or Ba 3. Fr or Cl

How strong is the nucleus? More p + = greater charge= e - pulled closer

1. Na or Rb 2. Ca or Se 3. S or Mg 4. Li or O

+ Nuclear charge Inner e - BLOCKS Valence e- from the nuclear charge( p+) b/c  E Level

1. Na or Rb 2. Sn or C 3. Br or F

+ E level Top of a group No  in E level  nuclear charge =  p + = stronger nucleus = valence e - are pulled closer

Atomic Radius ( under flap)

Atomic Radius

1. Li or Cs 2. Ga or B 3. O or C 4. Be or Ba 5. Si or S

Gain, lose, or share e - to be STABLE like Noble gases s 2 p 6 **Exception energy level 1

Cation (+) loses e - = more p + than e - GroupmustCharge 1loses 1 e Loses 2 e Loses 3e - 3+ Anion (-) gains e - = more e - than p + Groupmustcharge 15Add 3 e Add 2 e Add 1e Add or Lose e - based on what's EASIER

1. becomes Smaller 2. Lose valence e -, lose E level 3. More nuclear charge

Atom Ion Losing e - Lost E level

1. becomes Bigger 2. Gain valence e - 3. Less nuclear charge, weaker nucleus

Atom Ion add e - Same #p + BUT more e -

NonMetalMetal

1. Al 3+ or P K + or Cs + 3. O 2- or Te 2-

Energy needed to remove ONE e -

Top of a group Bigger = valence e - farther away= less E (easier) to remove e - lower IE Closer to being noble gas = more E (harder) to remove e - higher IE Ionization Energy

1. Na or S 2. Mg or Ba 3. Ga or Br 4. P or Bi

Electronegativity: BONDEDWANT likelihood BONDED atom WANT to take e - from another atom Like tug of war

Electronegativity

More E level & more e - = less likely to want more e - closer to being a noble gas = wants an e - Top of a group higher electroneg Lower electroneg

1. Na or Mg 2. K or Br 3. F or Br 4. Ca or Ga 5. Li or S 6. Br or As

Shielding is constant Atomic Radius decreases Ionization energy increases Electronegativity increases Nuclear charge increases Shielding increasesAtomic radius increasesIonization energy decreasesElectronegativity decreases

SAMPLE PROBLEM Ranking Elements by Atomic Size PLAN: SOLUTION: PROBLEM: Using only the periodic table (not Figure 8.15), rank each set of main group elements in order of decreasing atomic size: (a) Ca, Mg, Sr(b) K, Ga, Ca(c) Br, Rb, Kr(d) Sr, Ca, Rb Elements in the same group increase in size and you go down; elements decrease in size as you go across a period. (a) Sr > Ca > Mg These elements are in Group 2A(2). (b) K > Ca > Ga These elements are in Period 4. (c) Rb > Br > Kr Rb has a higher energy level and is far to the left. Br is to the left of Kr. (d) Rb > Sr > Ca Ca is one energy level smaller than Rb and Sr. Rb is to the left of Sr.

SAMPLE PROBLEMRanking Elements by First Ionization Energy PLAN: SOLUTION: PROBLEM:Using the periodic table only, rank the elements in each of the following sets in order of decreasing IE 1 : (a) Kr, He, Ar(b) Sb, Te, Sn(c) K, Ca, Rb(d) I, Xe, Cs IE decreases as you proceed down in a group; IE increases as you go across a period. (a) He > Ar > Kr (b) Te > Sb > Sn (c) Ca > K > Rb (d) Xe > I > Cs Group 8A(18) - IE decreases down a group. Period 5 elements - IE increases across a period. Ca is to the right of K; Rb is below K. I is to the left of Xe; Cs is further to the left and down one period.