Ionization Energy

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Ionization Energies 7 Be 900 Al 578 Si 787 Ti 659 V 651 Cr 653 Mn 717 Fe 762 Co 760 Ni 737 Cu 746 Zn 906 Ga 579 Ge 762 Nb 652 Mo 684 Tc 702 Ag 731 Cd 868 In 558 Sn 709 Sb 834 Ta 761 W 770 Re 760 Hg 1007 Tl 589 Pb 716 Bi 703 N 1402 O 1314 F 1681 Cl 1251 C 1086 S 1000 Br 1140 I 1008 Na 496 K 419 Rb 403 Cs 376 Ba 503 Fr -- Ra 509 H 1312 B 801 P 1012 As 947 Se 941 Ru 710 Rh 720 Pd 804 Te 869 Os 839 Ir 878 Pt 868 Au 890 Po 812 At -- Period Actinide series Li 520 Ca 590 Sc 633 Sr 550 Y 600 Zr 640 Hf 659 Mg 738 La 538 Ac 490 Lanthanide series     Group Ne 2081 Ar 1521 Kr 1351 Xe 1170 Rn 1038 He 2372 Rf -- Db -- Sg -- Bh -- Hs -- Mt -- Ce 534 Pr 527 Nd 533 Pm 536 Sm 545 Eu 547 Gd 592 Tb 566 Dy 573 Ho 581 Er 589 Tm 597 Yb 603 Lu 523 Th 587 Pa 570 U 598 Np 600 Pu 585 Am 578 Cm 581 Bk 601 Cf 608 Es 619 Fm 627 Md 635 No 642 Lr -- Ds -- Uub -- Uut -- Uuq -- Uup -- Uuu -- Mg 738 Symbol First Ionization Energy (kJ/mol) 810

First Ionization Energies (in kilojoules per mole) H Li Na K Be Mg Ca B Al Ga C Si Ge N P As O S Se F Cl Br Ne Ar Kr He Rb Sr In Sn Sb Te I Xe Smoot, Price, Smith, Chemistry A Modern Course 1987, page 188

First Ionization Energies (kJ/mol) H Li Na K Be Mg Ca B Al Ga C Si Ge N P As O S Se F Cl Br Ne Ar Kr He Rb Sr In Sn Sb Te I Xe Smoot, Price, Smith, Chemistry A Modern Course 1987, page 188 s p

First Ionization Energies (kJ/mol) H Li Na K Be Mg Ca B Al Ga C Si Ge N P As O S Se F Cl Br Ne Ar Kr He Rb Sr In Sn Sb Te I Xe Smoot, Price, Smith, Chemistry A Modern Course 1987, page 188 s p Metal Metalloid Nonmetal

First Ionization energy Atomic number H He n H e - 2e - Helium (He) has… a greater IE than H same shielding greater nuclear charge

First Ionization energy Atomic number Li has… lower IE than H more shielding Further away outweighs greater nuclear charge H He Li n

First Ionization energy Atomic number l Be has higher IE than Li l same shielding l greater nuclear charge H He Li Be n Li e - 1e - 2e - 1e - 2e e - 4+

First Ionization energy Atomic number l B has lower IE than Be l same shielding l greater nuclear charge l p-orbitals available H He Li Be B n B e - 3e - 2s 2p 1s 2e e - 2e - 5+

First Ionization energy Atomic number H He Li Be B C 2s 2p 1s n

First Ionization energy Atomic number H He Li Be B C N n 2s 2p 1s

First Ionization energy Atomic number H He Li Be B C N O n 2s 2p 1s Breaks the pattern because removing an electron gets to 1/2 filled p orbital

First Ionization energy Atomic number H He Li Be B C N O F n 2s 2p 1s

First Ionization energy Atomic number H He Li Be B C N O F Ne n 2s 2p 1s Ne has a lower IE than He Both are full energy levels, Ne has more shielding Greater distance

First Ionization energy Atomic number H He Li Be B C N O F Ne Na n 2s 2p 1s 3s Na has a lower IE than Li Both are s 1 Na has more shielding Greater distance

First Ionization energy Atomic number l Be has higher IE than Li l same shielding l greater nuclear charge H He Li Be n Li e - 1e - 2e -

First Ionization energy Atomic number l B has lower IE than Be l same shielding l greater nuclear charge l p-orbitals available H He Li Be B n B e - 3e - 2s 2p 1s

First Ionization energy Atomic number l Na has a lower IE than Li l Both are s 1 l Na has more shielding l Greater distance H He Li Be B C N O F Ne Na

First Ionization energy Atomic number HeNe Ar Kr H Li Na K Rb

First Ionization energy Atomic number He Ne Ar Kr H Li Na K Rb

First Ionization Energy Plot Atomic number First ionization energy (kJ/mol) H He Li Be B C N O F Ne Mg Na Al Si P S Cl Ar Ca K Sc Ti V Cr Mn Fe Co Cu Ni Zn Ga Ge As Se Br Rb Sr Kr

B 1+ B 5+ 2e - 3e - 2e - 3e - 2e e - 5+ nn B 2+ B e - 1e - 2e e - 2e - 5+ n B 3+ B e - 0e - 1e - 2e e - 2e - 5+ Boron B B 3+ vs. He 0e - 2e e - 2e - 5+ B 2+ vs. Li 1e - 2e e - 2e - 5+ B 1+ vs. Be 2e e - 5+ > > > < < < Isoelectronic B = 1s 2 2s 2 2p 1 B 1+ = Be = 1s 2 2s 2 B 2+ = Li =1s 2 2s 1 B 3+ = He = 1s 2

B 1+ B 3e - 2e e - 5+ nn B 2+ B 1+ 2e e - 2e - 5+ n B 3+ B 2+ 1e - 2e e - 2e - 5+ Boron B B 3+ vs. He 0e - 2e e - 2e - 5+ B 2+ vs. Li 1e - 2e e - 2e - 5+ B 1+ vs. Be 2e e - 5+ > > > < < < Isoelectronic B = 1s 2 2s 2 2p 1 B 1+ = Be = 1s 2 2s 2 B 2+ = Li =1s 2 2s 1 B 3+ = He = 1s 2

S 1- S S 2- S Sulfur S S 2- vs. Ar S 1- vs. Cl < < > > Isoelectronic S = 1s 2 2s 2 2p 6 3s 2 3p 4 S 1- = Cl 1s 2 2s 2 2p 6 3s 2 3p 5 S 2- = Ar 1s 2 2s 2 2p 6 3s 2 3p e - 8e - 6e e - 8e - 7e e - 8e - 7e e - 8e - 7e - n 16+ 2e - 8e - 7e e - 8e - 8e e - 8e - 8e e - 8e - 8e - n

Ionization Energies Energy is required to remove an electron from an atom to form a cation. Ionization energy (  ) is the amount of energy needed to remove an electron from the gaseous atom E in its ground state: E (g) +   E + (g) + e -- energy required for reaction = . Ionization energy is always positive (  > 0). Larger values of  mean that the electron is more tightly bound to the atom and is harder to remove. Units for ionization energies are kilojoules/mole (kJ/mol) or electron volts (eV) - 1 eV = kJ/mol. Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.

Ionization Energies (in kilojoules per mole) Element H He Li Be B C Al Smoot, Price, Smith, Chemistry A Modern Course 1987, page st nd rd th th th

Ionization Energies (kJ/mol) Element H He Li Be B C Al Smoot, Price, Smith, Chemistry A Modern Course 1987, page st nd rd th th th

Ionization Energies (kJ/mol) Element Na Mg Al Si P S Cl Ar Herron, Frank, Sarquis, Sarquis, Cchrader, Kulka, Chemistry 1996, Heath, page 1 st nd rd th ,600 11, th 13,400 13,600 15,000 16, th 16,600 18,000 18,310 19,800 21, Shaded area on table denotes core electrons.

Ionization Energies (kJ/mol) Element Na Mg Al Si P S Cl Ar Herron, Frank, Sarquis, Sarquis, Cchrader, Kulka, Chemistry 1996, Heath, page 1 st nd rd th ,600 11, th 13,400 13,600 15,000 16, th 16,600 18,000 18,310 19,800 21, Shaded area on table denotes core electrons.

ionization energy: the energy required to remove an e – from an atom M + 1st I.E. M + 2 nd I.E. M + 3 rd I.E. As we go, 1st I.E…. M 1+ + e – M 2+ + e – M 3+ + e – removes 1 st e – Each successive ionization requires more energy than the previous one. decreases. increases. (due to the shielding effect)

Multiple Ionization Energies Al Al + Al 2+ Al kJ/mol e kJ/mol e kJ/mol e - The second, third, and fourth ionization energies of aluminum are higher than the first because the inner electrons are more tightly held by the nucleus. 1 st Ionization energy 2 nd Ionization energy 3 rd Ionization energy Smoot, Price, Smith, Chemistry A Modern Course 1987, page 190

Ionization Energies It takes more energy to remove the second electron from an atom than the first, and so on. There are two reasons for this trend: 1. The second electron is being removed from a positively charged species rather than a neutral one, so more energy is required. 2. Removing the first electron reduces the repulsive forces among the remaining electrons, so the attraction of the remaining electrons to the nucleus is stronger. Energy required to remove electrons from a filled core is prohibitively large and simply cannot be achieved in normal chemical reactions. Copyright © 2007 Pearson Benjamin Cummings. All rights reserved.

Factors Affecting Ionization Energy Nuclear Charge The larger the nuclear charge, the greater the ionization energy. Shielding effect The greater the shielding effect, the less the ionization energy. Radius The greater the distance between the nucleus and the outer electrons of an atom, the less the ionization energy. Sublevel An electron from a full or half-full sublevel requires additional energy to be removed. Smoot, Price, Smith, Chemistry A Modern Course 1987, page 189

27dFields-Jeff/Period1.htm Ionization Energies KeysKeys Ionization Energies GraphGraph

Driving Force Full Energy Levels are very low energy. Noble Gases have full orbitals. Atoms behave in ways to achieve noble gas configuration.

2nd Ionization Energy For elements that reach a filled or half filled orbital by removing 2 electrons 2nd IE is lower than expected. True for s 2 Alkali earth metals form +2 ions.

3rd IE Using the same logic s 2 p 1 atoms have an low 3rd IE. Atoms in the aluminum family form + 3 ions. 2nd IE and 3rd IE are always higher than 1st IE!!!

Electron Affinity The energy change associated with adding an electron to a gaseous atom. Easiest to add to group 17. Gets them to full energy level. Increase from left to right atoms become smaller, with greater nuclear charge. Decrease as we go down a group.

Ionic Size Cations form by losing electrons. Cations are smaller that the atom they come from. Metals form cations. Cations of representative elements have noble gas configuration.

Ionic size Anions form by gaining electrons. Anions are bigger that the atom they come from. Nonmetals form anions. Anions of representative elements have noble gas configuration.

Formation of Cation 11p + sodium atom Na e-e- loss of one valence electron e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- sodium ion Na + 11p + e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e-

Formation of Anion 17p + chlorine atom Cl e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- gain of one valence electron chloride ion Cl 1- 17p + e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e-

Formation of Ionic Bond chloride ion Cl 1- 17p + e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- sodium ion Na + 11p + e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e- e-e-

Atoms and Ions