4 ms·

What a coincidence, I stumbled upon this page very recently! I like the left-step one actually, it makes so much sense, more than the standard one in fact I wo

What a coincidence, I stumbled upon this page very recently! I like the left-step one actually, it makes so much sense, more than the standard one in fact I would say (but I'm not a chemist though)

jcranmer 8y ago
The left-step one actually disguises a few important facts from the normal periodic table. The obvious one is that He (which is only a full s shell) is far more similar to elements with full p shells than those with only a full s shell. In terms of bonding, the outermost s and p shell influences bonding the most. He, who has no p shell, acts far more like an element that has a full p shell than an element that only has a full s shell and an empty p shell because of the influence of the p shell on bonding, so you do want to stick He in the same group as Ne, Ar, Kr, Xe, and Rn. The other thing that is tricky is where the f block starts to integrate in the table. The f shell of electrons is far less involved in bonding and observable effects than the d shell is. Furthermore, even the basic electron configuration breaks down because the f and d blocks are so similar in energy. La and Ac both fill their first d electron before the f electron, and several actinides actually retain this single outermost d electron rather than dumping everything in the f block. There is some dispute as to whether or not you should put La/Ac in the d block, or Lu/Lr in the d block, or instead put the entire La-Lu/Ac-Lr block in that one-element hole (this is perhaps one of the reasons why people like using the short form a lot--you can be somewhat vague here).
- madcaptenor 8y ago
  I haven't thought about chemistry in a while, but He as an alkaline earth metal just makes me laugh. (I have seen layouts where H is above F, though, and I can get behind that...)
- kylek 8y ago
  >> He, who has no p shell, acts far more like an ... Sorry (downvotes...incoming), but this sounds the great start to a double entendre.

What a coincidence, I stumbled upon this page very recently! I like the left-step one actually, it makes so much sense, more than the standard one in fact I would say (but I'm not a chemist though)

jcranmer 8y ago

The left-step one actually disguises a few important facts from the normal periodic table. The obvious one is that He (which is only a full s shell) is far more similar to elements with full p shells than those with only a full s shell. In terms of bonding, the outermost s and p shell influences bonding the most. He, who has no p shell, acts far more like an element that has a full p shell than an element that only has a full s shell and an empty p shell because of the influence of the p shell on bonding, so you do want to stick He in the same group as Ne, Ar, Kr, Xe, and Rn. The other thing that is tricky is where the f block starts to integrate in the table. The f shell of electrons is far less involved in bonding and observable effects than the d shell is. Furthermore, even the basic electron configuration breaks down because the f and d blocks are so similar in energy. La and Ac both fill their first d electron before the f electron, and several actinides actually retain this single outermost d electron rather than dumping everything in the f block. There is some dispute as to whether or not you should put La/Ac in the d block, or Lu/Lr in the d block, or instead put the entire La-Lu/Ac-Lr block in that one-element hole (this is perhaps one of the reasons why people like using the short form a lot--you can be somewhat vague here).

madcaptenor 8y ago
I haven't thought about chemistry in a while, but He as an alkaline earth metal just makes me laugh. (I have seen layouts where H is above F, though, and I can get behind that...)
kylek 8y ago
>> He, who has no p shell, acts far more like an ... Sorry (downvotes...incoming), but this sounds the great start to a double entendre.