Presentation on theme: "Electron configuration: is how electrons are organized within atoms."— Presentation transcript:
1 Electron configuration: is how electrons are organized within atoms. 4p3d4ss1 2p13p2d33s452p672sfElectron configuration: is how electrons are organized within atoms.1s
2 Rules of Electron Configuration: Aufbau principle: Electrons enter orbitals of lowest energy first. Pauli exclusion principle: An atomic orbital may describe at most two electrons Hund’s rule: When electrons occupy orbitals of equal energy, one electron enters each orbital until all the orbitals contain one electron with parallel spins.
3 4d5s4p3d4ss1 2p13p2d33s452p672sfOK, so we’re going to use arrows pointing up or down to represent the electrons. Can you guess into which box the first electron would go given that it is attracted to the nucleus?1s
4 4d5s4p3d4ss1 2p13p2d33s452p672sHf1s1That’s right: it goes in the 1s sublevel. And its el. config is 1s1. Notice in the table above where H is – in the area designated as 1s. So where does the next electron go?1s
5 Electron Configuration: Shorthand Notation: -Coefficient: energy level -Lower case letter: type of subshell -Superscript: # of electons in subshell
6 4d5s4p3d4ss1 2p13p2d33s452p672sHef1s2If you were thinking it went in the 2s, then you forgot that each orbital can hold up to two electrons. Note how He is right here in the area designated as 1s2 and so its el. config. is 1s2.1s
7 4d5s4p3d4ss1 2p13p2d33s452p672sLif1s2 2s1Now that the 1s is filled, the next electron goes in the next sublevel – the 2s. Again note how Li is in 2s1.1sIts full el. conf. is 1s2 2s1. What is Be’s el. conf?
8 4d5s4p3d4ss1 2p13p2d33s452p672sBef1s2 2s2Is this what you were thinking? Good. Now look at the periodic table above, what comes after the 2s sublevel?1sThe 2p sublevel. So what will the next el. conf. be?
9 4d5s4p3d4ss1 2p13p2d33s452p672sBf1s2 2s2 2p1Is this what you were thinking? Notice how B is in the 2p1 spot.1sSo its full el. conf. is 1s2 2s2 2p1. What’s next?
10 4d5s4p3d4ss1 2p13p2d33s452p672sCf1s2 2s2 2p2Is this what you were thinking? Notice how C is in the 2p2 spot. So its el. conf. is 1s2 2s2 2p21sNotice also how when we fill a sublevel…
11 4d5s4p3d4ss1 2p13p2d33s452p672sNf1s2 2s2 2p3…we put one electron in each orbital until the sublevel is half filled…1s
12 4d5s4p3d4ss1 2p13p2d33s452p672sOf1s2 2s2 2p4… and then we go back and start pairing off1sThis is called “Hund’s Rule, but it also referred to as the bus seat rule. Can you figure out why?
13 4d5s4p3d4ss1 2p13p2d33s452p672sFf1s2 2s2 2p5Look at F. It’s just one electron away from having filled 2p sublevel…1sAnd it’s just one square away from the end of the 2p block.
14 4d5s4p3d4ss1 2p13p2d33s452p672sNef1s2 2s2 2p6And then Ne has a completely filled outer level. Na is next. Can you guess where the next electron is going to go?1s
15 Na 1s2 2s2 2p6 3s1 4d 5s 4p 3d 4s s p 1 3p 2 d 3 3s 4 5 2p 6 7 2s f 1s 1 2p13p2d33s452p672sNaf1s2 2s2 2p6 3s1That’s right: in the 3s sublevel. Right now, write down in your notebook what you think the next three el configs will be.1s
16 Mg 1s2 2s2 2p6 3s2 4d 5s 4p 3d 4s s p 1 3p 2 d 3 3s 4 5 2p 6 7 2s f 1s 1 2p13p2d33s452p672sMgf1s2 2s2 2p6 3s2Did you get this one right?1s
17 4d5s4p3d4ss1 2p13p2d33s452p672sAlf1s2 2s2 2p6 3s2 3p1How about Al’s? See how Al is in the 3p1 spot on the per table1sand its el config ends with 3p1
18 4d5s4p3d4ss1 2p13p2d33s452p672sSif1s2 2s2 2p6 3s2 3p2Now just advance through the next 23 slides, but as you do, make sure you are understanding1s
19 4d5s4p3d4ss1 2p13p2d33s452p672sPf1s2 2s2 2p6 3s2 3p3Exactly what is going on… how the el configs simply follow the sequence of the periodic table.1s
20 4d5s4p3d4ss1 2p13p2d33s452p672sSfYour goal by the end of this slide show is to be able to write el configs for any element using just the periodic table – and your brain!1s2 2s2 2p6 3s2 3p41s
35 Ga 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p1 4d 5s 4p 3d 4s s p 1 3p 2 d 3 3s 4 1 2p13p2d33s452p672sGaf1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p11s
36 Ge 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p2 4d 5s 4p 3d 4s s p 1 3p 2 d 3 3s 4 1 2p13p2d33s452p672sGef1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p21s
37 As 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p3 4d 5s 4p 3d 4s s p 1 3p 2 d 3 3s 4 1 2p13p2d33s452p672sAsf1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p31s
38 Se 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p4 4d 5s 4p 3d 4s s p 1 3p 2 d 3 3s 4 1 2p13p2d33s452p672sSef1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p41s
39 Br 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p5 4d 5s 4p 3d 4s s p 1 3p 2 d 3 3s 4 1 2p13p2d33s452p672sBrf1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p51s
40 Kr 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 4d 5s 4p 3d 4s s p 1 3p 2 d 3 3s 4 1 2p13p2d33s452p672sKrf1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p61s
41 Rb 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s1 4d 5s 4p 3d 4s s p 1 3p 2 d 3 1 2p13p2d33s452p672sRbf1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s11s
42 So, the pattern for reading the electron configurations right off the periodic table is this: 11s222s22p633s23p644s23d104p655s24d105p666s25d106p677s26d104f145f14
43 The short cut would be: [Ne]3s2 3p5 For example, Cl (#17) which is right here on the table:So the answer would be 1s2 2s2 2p6 3s2 3p5The short cut would be: [Ne]3s2 3p511s222s22p633s23p54567
44 1s2 2s2 2p6 3s2 3p6 4s2 3d8 Short cut: [Ar] 4s2 3d8 1 2 3 4 5 6 7 Or how about Ni (#28)1s2 2s2 2p6 3s2 3p6 4s2 3d8Short cut: [Ar] 4s2 3d811s222s22p633s23p644s23d8567
45 Exceptions: Some configurations don’t follow the Aufbau principle because….
46 Some configurations don’t follow the Aufbau principle because: Exceptions:Some configurations don’t follow the Aufbau principle because:Filled energy levels are more stable than partially filled onesHalf filled ones are more stable than partially filled ones
47 Exceptions to the Electron Configuration Rules Examples:ChromiumWrong: 1s22s22p63s23p64s23d4Right: 1s22s22p63s23p64s13d5CopperWrong: 1s22s22p63s23p64s23d9Right: 1s22s22p63s23p64s13d10
48 Exceptions to the Electron Configuration Rules Example: What is the electron configuration for rubidium?Solution:Rb: 1s22s22p63s23p64s23d104p65s1Example: What is the electron configuration for silver?Ag: 1s22s22p63s23p64s23d104p65s24d9(half-filled s level more stable than partially-filled d level) 1s22s22p63s23p64s23d104p65s14d10
49 ELECTRON CONFIGURATION BATTLESHIP!! Mark 6 ships on your periodic table.One partner will call out the electron configuration notation. The other partner will confirm the element before replying with “hit” or “miss.”