(b) What are “core electrons”?

Question

Accepted Answer

welcome back everyone in this example. We need to identify the statement that does not describe core electrons. So beginning with statement A it reads that core electrons don't participate in chemical bonding. So we want to recall what core electrons are and core electrons are considered inner shell electrons. So they're not valence electrons. Whereas according to statement A these inner shell electrons would not participate in chemical bonding. And we would actually agree with this as true because we recall that only valence electrons or outer shell electrons participate in bond in bonding. Which is why we have to calculate valence electrons and formal charges to maintain stable structures when we're drawing out things like lewis structures and molecules. So let's move onto choice B. Because we can rule out choice A Since we want to click where we want to choose a false statement. Moving onto statement B. It says that core electrons are paired electrons. We would also recognize this statement as true and that is due to the fact that core electrons are placed and filled orbital's and if they're filled they're fully filled. So there's not gonna be any empty orbital's and so therefore they're always paired up. We could rule out choice B because it's another false statement. Moving on to choice. See it says that core electrons, we're sorry, choice B is another true statement as we stated. But choice C says that core electrons have the electron configuration of the nearest noble gas element. We would also recognize statement C. As a true statement and that is due to the fact that we can write out electron configurations using our noble gas element. And so that means that electrons in excess of the noble gas configuration, our valence electrons. So we would rule out Choice C. Because it's another true statement that does correctly describe core electrons moving onto Choice D. It says that core electrons are outer shell electrons and above we stated core electrons are inner shell electrons, Outer shell electrons refer to valence electrons, and so again, core electrons are inner shell. So statement D does not describe core electrons. And so therefore we would confirm that statement. D is the correct choice to complete this example as the statement that does not describe core electrons accurately. If you have any questions, leave them down below and I'll see everyone in the next practice video.

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