Unformatted text preview: greater than first IE. The third IE is the energy required to remove a third electron. Greater than 1st or 2nd IE. Ionization Energies Table 12.1, p. 281 kJ/ mol Symbol First
H He Li Be B C N O F Ne Atom 1312 2731 520 900 800 1086 1402 1314 1681 2080 Second
5247 7297 1757 2430 2352 2857 3391 3375 3963 Third
Ion Formed 11810 Be 14840 3569 2+ 4619 4577 5301 6045 6276 What determines IE
The greater the nuclear charge, the greater IE. Greater distance from nucleus decreases IE Filled and halffilled orbitals have lower energy, so achieving them is easier, lower IE. Shielding effect Shielding The electron on the outermost energy level has to look through all the other energy levels to see the nucleus. Second electron has same shielding, if it is in the same period + Group trends
As you go down a group, first IE decreases because... The electron is further away. More shielding. Periodic trends
All the atoms in the same period have the same energy level. Same shielding. But, increasing nuclear charge So IE generally increases from left to right. Exceptions at full and 1/2 full orbitals. H...
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