Electron Configuration Quiz: Fill & Download for Free

I finished high school in 1975 and have a degree in Chemistry.In my undergraduate course of Chemistry, there was one student of hundreds who learnt it. The rest of us did not.However, it is extremely important to understand the relationship between electron configuration from quantum theory and the overall structure of the periodic table. This enables you to gain the full richness when you look it up. It is really like an encyclopaedia on one page.If you have a teacher who says you must learn it and the teacher will quiz you on that, try to go for a full understanding rather than rote learning.Even looking it up does not help you much if you do not understand it at a deep level.Besides,these days there are so many more elements in it than when I was young. :p

Honestly, everything. I'll list a bunch of reasons.# 1. Grade-based learning. Everything in HS is grade-centered. Students/parents are constantly obsessing over grades rather than the actual material. When I asked my chemistry teacher if I could avoid experiments, he said '' Oh, don't worry, you'll pass.'' ( Note: The teacher wasn't bad at all but I was disillusioned with the idea of ''passing'' as an educational achievement)# 2. People. You have the spend 100 % of your day with 50 + people who are loud, boisterous, and don't care about you. You wake up early to only hear yelling in the cafeteria and slouch insouciantly in hallways filled with 70 kids shouting about that stupid AP Bio quiz/snapchat post/smoking weed/other teenage idiosyncrasies. Adults tell you '' HS is the definitive foundation for your life'', but I honestly feel like dropping out. I have to deal with people who don't greet me, make fun of me, and generally don't care if I put a bullet up my head. It's been incredibly disillusioning. Giving my soul/heart in a place to people who don't care is awful, and it's something NOBODY should go through.# 3. Lack of personalization. It's incredibly difficult to individualize learning in a class filled with 30 kids. Some kids blaze right through the textbook, others remain confused by the complexity of intricate math formulas, and some feel bored to the core by Darwin's finches. HS flat-out fails when it comes to designing a personal learning plan for every student. ( Unless if you have severe issues) While I do understand that every student should have a basic foundation in core academia, don't tell me you used mitosis to cook meals, need electron configuration to change my classes, used SAS/conic sections to make business decisions/you get the shtick. I'm sorry, but there's nothing epiphanic or life-changing about reluctantly learning the periodic table. Period. ( Pun intended)# 4. Lack of real-life applications. HS learning is devoid of real-life applications.# 5. The mindless sensationalization about SAT, College, and AP's. People get bogged-down in this ''oh my god i gotta get a perfect A in APUSH and pre-calc so i can go to NYU or Harvard''. This type of attitude is rampant amongst HS students.

This is a good question. Yes, since you’ve learned that the maximum number of electrons in each shell is given by 2n², you would expect the 3rd. shell to be able to take up to 18 electrons so that 2.8.9 would be perfectly reasonable.Of course the Periodic table has potassium as the first element on the 4th row, so we know it has 4 shells not 3, and that it has one electron in that outer fourth shell because it’s in Group I like Li and Na. So the table tells us that its configuration is actually 2.8.8.1, but that still leaves us with the question: why isn’t K using the space (for 10 more electrons) that we know still exists in its 3rd shell?If you move along to calcium, there’s the same problem. It’s in Group II with 2 electrons in its outer shell: 2.8.8.2 and there’s still that space left in the 3rd shell.So what’s next? Scandium, first of a row of… 10 elements. Any guesses what’s happening here? Yes, this is where we finally get to use that extra space.You can see that by the time we get to zinc, we finally get a full 3rd shell and 2.8.18.2. Two electrons on the outside and three inner full shells. No wonder that Mendeleev put zinc with the Group IIs initially, with its white/colourless compounds and properties so similar to Mg and Ca.I can see another response has mentioned the s, p, d, and f orbitals and the Aufbau principle and all that. But I wanted to show you that you can make quite a few logical steps first.I’m going to deal with the orbital thing first before answering your question - so if this is something you think you want to skip, then scroll to the end.OK, so what is it with s, p, d, and f ? These are the names given to regions of space - called sub-shells - available within each shell where electrons can hang out. [there is a reason why these letters were used: not too important now, but perhaps good for a trivia quiz]It turns out that there’s an important rule that no two identical electrons can occupy the same space, which always puts me in mind of the 1994 film Time Cop. This means that electrons take up particular regions of space inside each shell. And because there’s one way that electrons can be non-identical by having opposite spins, you can have pairs of electrons in each of these ↑ and ↓.The first bit of space is called the s-orbital. It’s a region that looks like the skin of an orange. Only one pair of electrons can live here. It’s the easiest bit of space to define so even the tiny first shell has an s-orbital.If you’d like to draw a circle to represent that first s-orbital, you can draw another circle around it which we can call the s-orbital of the second shell. You’ll see that there’s a bit of space between these concentric circles and that perhaps could be used for electrons.The ‘in-between’ space is divided up into three p-orbitals:theeach of which can take one pair of electrons.Can you see why the first shell can take 2 electrons and the second takes 8?The first shell’s space only allows one s-orbital and accommodates 2 electrons. The second shell gets to have one s-orbital and three p-orbitals, so 2+(3x2)=8 electrons. We can write the sub-shells and the numbers of electrons they can take as 1s² and 2s² and 2p⁶.If you draw a bigger third concentric circle and mark out some space for the 2p orbitals and now some similarly-shaped 3p orbitals, you’ll discover that there are some significant pockets of space amongst the 3p orbitals. This space can actually be apportioned to produce five d-orbitals - which are a little oddly shaped:But with five orbitals, the d-sub-shell can accommodate (5x2)=10 electrons.At this stage, the actual shapes of the orbitals are not as important as simple how much space they represent: the s-orbital can take up to 2 electrons; the three p-orbitals can take up to 6 electrons; the five d-orbitals can fit up to 10 electrons.So now we can write out the electronic configuration of K showing exactly where all the electrons are. So instead of just 2.8.8.1, we can write 1s² 2s² 2p⁶ 3s² 3p⁶ 4s¹So what about your question: Why start filling the 4s when there’s still space in the 3d? In fact, in terms of energy level, 4s and 3d are very similar. It’s a little bit like buying a nice box for a birthday present. There’s a box that holds one or two things and there’s a box that’s divided up so it can take ten. The boxes are the same price, so given that you only have one or two things to pack have an electron spread all over an s-orbital seems nicer than having it rattling around in a little corner of a big box.I’m a bit mindful here about simply saying 4s is at lower energy, like a lower rung on the energy ladder, because I know that when the transition metals lose electrons to make ions, these always come out of the 4s first and only from the 3d afterwards.Btw, if you have a Periodic table to hand, then you should know that it can help you to know where how an element’s electrons are arranged in the orbitals:OK, that’s it for now… hope it helps!