Chem 1061 1st Edition Lecture 21Outline of Last Lecture 1. Energy Levels in H atom2. Ionization Energy3. Conversions4. Energy Levels in H Atom5. Absorbance6. Wave Particle DualityOutline of Current Lecture 7. Energy Splitting with Multiple Electronsa. Electrostatic Effectsi. Nuclear Chargeii. Electron Repulsionsb. Inner Orbitalsc. Penetration8. Electron ConfigurationCurrent LectureEnergy Splitting with Multiple ElectronsM, l, and m(l) describe the orbitalM(s) describes the electronNo two electrons in the same orbital can have the same four quantum numbers (QNs) [exclusion principle]Electrostatic Effects a) nuclear chargeHow does the number of protons (Z) in nucleus affect electron energy?Z=1 (H) 1s electronZ=2 (He+) 1s electronZ=3 (Li2+) 1s electronAll are one electron specie, but have a different ZThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Compare Ionization Energy.Ionization energy is a measure of how strongly an electron is attracted to the nucleus.H= 1311 KJHe+=5250 KJLi2+=11615 KJMore protons (higher nuclear charge) = stronger attractionIt is more difficult to remove electron requires more energyb)Electron Repulsionssame orbital (He vs He+)He to remove = 2372 KJ/molHe+ to remove = 5250 KJ/molHigher ratio of protons to electrons make it easier to removeExample mom and dad has divided attention with two kids (e-) in comparison to undivided with one kid (e-)2) Inner Orbitals (shielding/net nuclear charge Z(eff))Li vs Li2+Li to remove = 520 KJ/molLi2+ to remove = 2954 KJ/molExample older children (bigger) can get away from mom and dad have more freedom because the mom and dad are focused on the small child (e-) but when it is only the older child they focus more on you (e-) (no screening of other electrons on outer)Greater shielding by inner electronsEasier to take e- from Li atom because of repulsion from 2e- in 1s orbital. shield effective nuclear charge; reducing Z(eff).3) PenetrationHow do we know e- in 2s is lower in energy than 2p?2s spends more time closer to nucleus than 2p.Energy within a given shell.S>P>D>FFilling in orbitals with e-lowhigh E (fill periodic table)Electron ConfigurationLs(1) l= n values= l value1= how many e- in orbital
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