Atomic Structure and Chemical Periodicity Atomic Size Quantum

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Atomic Structure and Chemical Periodicity

Atomic Structure and Chemical Periodicity

Atomic Size – Quantum mechanical model doesn’t sharply define boundary to limit size –

Atomic Size – Quantum mechanical model doesn’t sharply define boundary to limit size – Atomic radius: ½ the distance between nuclei of 2 like atoms in a diatomic molecule • • Atomic radius

Atomic size

Atomic size

Atomic Size Increasing Atomic Size “Fatty Francium” Atomic Size Increasing

Atomic Size Increasing Atomic Size “Fatty Francium” Atomic Size Increasing

Octet Rule: atoms want 8 e- in their valence energy level Ionization Energies: amount

Octet Rule: atoms want 8 e- in their valence energy level Ionization Energies: amount of energy required to remove an electron from the valence shell of an atom Nobel Gases - don’t want to lose e- so they have very high ionization energy Li - doesn’t take much energy to lose e-, low ionization energy F - wants to gain an e- , therefore takes large amount of energy to pull off an e-, high ionization energy

Examples • Which atom has the larger radius? –Be or Ba Ba –Ca or

Examples • Which atom has the larger radius? –Be or Ba Ba –Ca or Br Ca

▫ As you move down a group the ionization energy decreases b/c of the

▫ As you move down a group the ionization energy decreases b/c of the shielding effect e- e- e- + e- e- Inner e- tend to push outer eaway from the nucleus b/c both have negative charges e- e- ▫ As a result of this shielding effect outer e- are less tightly bound to the nucleus than inner e-

D. Ionization Energy (cont. ) Ionization Energy Increase

D. Ionization Energy (cont. ) Ionization Energy Increase

Ionic Size • Ion – positively (cation) or negatively (anion) charged atom, gains or

Ionic Size • Ion – positively (cation) or negatively (anion) charged atom, gains or loses electrons

Ionic Size Increase Cations Increase Anions Increase

Ionic Size Increase Cations Increase Anions Increase

Examples • Which atom has the higher ionization energy –N or Bi –Ba or

Examples • Which atom has the higher ionization energy –N or Bi –Ba or Ne N Ne

Electronegativity • The electronegativity of an element is the tendency for the atoms to

Electronegativity • The electronegativity of an element is the tendency for the atoms to attract e- when they are chemically combined with another element • Noble Gases have NO electronegativity b/c they don’t gain e • Increase from left to right b/c of octet rule • Decrease when move down a group b/c of shielding effect

E. Electronegativity (cont. ) Electronegativity Increase

E. Electronegativity (cont. ) Electronegativity Increase

F. Summary of Trends Periodic Table of the Elements Atomic Size Increasing Fr “Fatty

F. Summary of Trends Periodic Table of the Elements Atomic Size Increasing Fr “Fatty Francium” Ionic Size Increasing F Electronegativity Increase Atomic Size Increasing Ionization Energy Increase “Friendly Fluorine” Ionization Energy Increase Ionic Size Increasing Electronegativity Increase

Whiteboard Practice Which of these elements has a larger atomic size? 1. Li or

Whiteboard Practice Which of these elements has a larger atomic size? 1. Li or K 3. Te or I 2. C or O elements in 4. order Ca or Arrange these of. Kincreasing atomic size. S, Cl, Al, Na Answer: Cl, S, Al, Na Is this a period trend or a group trend? Answer: Period trend

White Board Practice Write the element with the greatest value for Ionization Energy. 1.

White Board Practice Write the element with the greatest value for Ionization Energy. 1. Al or P 3. O or Ne 2. Ca or Ni 4. Zr or Cs Rank the sets of atoms from smallest to largest for Electronegativity. 1. Se, Cr, Zn, Se 2. P, Ar, Mg, P

Atomic Size War! • Each card has an element symbol. • You will flip

Atomic Size War! • Each card has an element symbol. • You will flip over one card and place it on the table and your partner will do the same. • Who ever has the Element with the GREATER atomic size Wins those two elements. • You continue to each flip over cards until one player has all the elements. • If you flip over the same element you will each turn over one more card and the player with the greater atomic size will win all four cards. • Separate the cards and shuffle and play a new game using a different trend.