Identify the specific element that corresponds to each of the
fo...

Question

Identify the specific element that corresponds to each of the 
following electron configurations and indicate the number 
of unpaired electrons for each: (c) 3Ar44s13d5

Accepted Answer

Hi everyone for this problem. It says consider the electron configuration, identify the element that corresponds to the electron configuration and identify the number of UNP aired electrons. So let's start off with identifying the element. The way that we're going to identify the element is we're going to add the superscripts and the atomic number of the noble gas to determine the number of electrons. So our noble gas here is argon and looking at our periodic table, the atomic number of argon is 18. And we have to superscripts here. So we're going to add those. So we have plus two and plus seven. So this gives us 27 electrons. Now remember that in a neutral atom? The atomic number tells us the number of protons and electrons and that number is going to be equal. Okay, so here we know we have 27 electrons. So when we go to our periodic table, we're going to look for the atomic number 27. And when we find that we see that it is cobalt. Okay. And this is the the symbol for cobalt. Alright, so that is our element. We just identified the element. The next thing we're asked to do is to identify the number of UNP aired electrons. So for us to do this, we're going to need to recall our sub shells. And how many electrons they each hold. Okay, so R S sub shell holds a maximum of two electrons are p Sub shell holds a maximum of six electrons are d Sub shell holds a maximum of 10 electrons. And our f sub shell holds a maximum of electrons. All right, so let's go ahead and write in how many orbital's we have? So, R S sub shell only has one orbital and it holds a maximum of two. Remember that? We have one orbital holds two electrons. So that means R P sub shell has three orbital's R D. Sub shell has five orbital's And our f sub shell has six orbital's. So we're gonna go ahead and fill in these orbital's to see how many unpaid electrons we have. Okay, and two important rules we need to remember when filling in orbital's is the off bob principle is we're going to totally fill in the lowest energy orbital first, which is our S and huns rule, it tells us the aleck on orbital's that are degenerate are the first half filled. Our first half filled before they are totally filled. So looking at our electron configuration here, we see that our S sub shell has two electrons. Okay, so we'll go ahead and fill in those two. So that is completely filled. Our d orbital has seven electrons. Okay, so 1234567. Alright, And so what this means is the the first five will fill one orbital each, then the last two will be paired. So that means we have three UNP aired electrons. So our answer here is three unpaid aired electrons. All right. So that's it for this problem. I hope this was helpful

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