Periodicity Periodic Table Trends

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

3 factors that effect Periodic Trends

1. Energy level (front of first flap) (on back of flap) Rings/orbits/ shells: “how far out the e- cloud spans” More E levels= valence e- further away from nucleus

1. Energy level (draw under flap)

(on back of sheet) Who has more Energy Levels? Ca or Ge Al or Ba Fr or Cl

(2nd flap front) 2. Nuclear Charge (# protons) (back) How strong is the nucleus. The more p+ the greater the charge, the stronger the pull on the e- , which pulls them in closer & makes the atom smaller!! Ie. More p+ = greater charge= e- pulled closer

(under) 2. Nuclear Charge (# protons)

(behind) Nuclear Charge- Who has more? Na or Rb Ca or Se S or Mg Li or O

(3rd flap) 3. Shielding effect Nuclear charge Inner e- BLOCKS + Valence e- from the nuclear charge( p+) b/c  E Level (back)

(under) 3. Shielding effect

(back) Who has more shielding effect? Na or Rb Sn or C Br or F

4. Atomic Radius

(back flap for atomic radius) Top of a group No  in E level  nuclear charge =  p+ = stronger nucleus = valence e- are pulled closer + E level

Atomic Radius ( under flap) Fatty Fatty Francium!!!

Atomic Radius

Which atom is bigger & Why? Li or Cs Ga or B O or C Be or Ba Si or S

(front) 5. Ionization Energy (IE)

Ionization Energy- energy needed to remove 1 e- (back) Ionization Energy- energy needed to remove 1 e- higher IE Top of a group Closer to being noble gas = more E (harder) to remove e- Bigger = valence e- farther away= less E (easier) to remove e- lower IE

Ionization Energy Measured in kJ/mole Ex: It takes 520 kJ to ionize 1 mole of Li

Which atom has larger (1st ) Ionization Energy ? 1. Na or S 2. Mg or Ba 3. Ga or Br 4. P or Bi

2nd , 3rd ….Ionization Energies The 1st electron is the easiest to remove It take more energy to remove a 2nd electron than it did the 1st and so forth

(front) 6. Electronegativity (back) Ability to attract e- into a chemical bond Like tug of war

Electronegativity higher Electroneg. Top of a group More E level & more e- = less likely to want more e- The More Valence e- you have the closer you already are to being a noble gas. Fluorine is the most Electronegative element Lower electroneg

Does NOT include the Nobel Gases

Which atom has higher Electronegativity? Na or Mg K or Br F or Br Ca or Ga Li or S Br or As

7. Octet Rule = 8 (valence e-) (back) Gain, lose, or share e- to be STABLE like Noble gases s2p6 **Exception energy level 1 Hydrogen only wants 1 more e- to be like He (already stable)

Ions: atoms trying to obey the octet rule will… Gain or Lose e- based on what's EASIER Cation (+) loses e- = positive ion Anion (-) gains e- = negative ion Group must Charge 1 loses 1 e- 1+ 2 Loses 2 e- 2+ 13 Loses 3e- 3+ Group must charge 15 Add 3 e- 3 - 16 Add 2 e- 2 - 17 Add 1e- 1 -

Metal ION Size 1. Lose valence e- , lose E level 2. Stronger nuclear charge = becomes smaller

Metal ION Size Atom Losing e- Ion Lost E level

Non-Metal ION Size Gain valence e- Weaker nuclear charge = become BIGGER

Non-Metal ION Size Ion add e- Atom Same #p+ BUT more e-

Metal NonMetal

Which ion in each, is smaller? 1. Al3+ or P3- 2. K+ or Cs+ 3. O2- or Te2-

Summary Ionization energy decreases Electronegativity decreases Nuclear charge increases Atomic radius increases Shielding increases Shielding is constant Atomic Radius decreases Ionization energy increases Electronegativity increases Nuclear charge increases

Ranking Elements by Atomic Size Warm Up 3.1 Ranking Elements by Atomic Size 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 PLAN: Elements in the same group increase in size and you go down; elements decrease in size as you go across a period. SOLUTION: These elements are in Group 2A(2). (a) Sr > Ca > Mg These elements are in Period 4. (b) K > Ca > Ga Rb has a higher energy level and is far to the left. Br is to the left of Kr. (c) Rb > Br > Kr Ca is one energy level smaller than Rb and Sr. Rb is to the left of Sr. (d) Rb > Sr > Ca

(a) Kr, He, Ar (b) Sb, Te, Sn (c) K, Ca, Rb (d) I, Xe, Cs Warm Up 3.2 Ranking Elements by First Ionization Energy PROBLEM: Using the periodic table only, rank the elements in each of the following sets in order of decreasing IE1: (a) Kr, He, Ar (b) Sb, Te, Sn (c) K, Ca, Rb (d) I, Xe, Cs PLAN: IE decreases as you proceed down in a group; IE increases as you go across a period. SOLUTION: (a) He > Ar > Kr Group 8A(18) - IE decreases down a group. (b) Te > Sb > Sn Period 5 elements - IE increases across a period. (c) Ca > K > Rb Ca is to the right of K; Rb is below K. (d) Xe > I > Cs I is to the left of Xe; Cs is further to the left and down one period.