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

Question

Identify the specific element that corresponds to each of the
following electron configurations and indicate the number
of unpaired electrons for each: (a) 1s22s2

Accepted Answer

Hi everyone for this problem. It reads consider the electron configuration, identify the element that corresponds to the electron configuration and identify the number of UNP aired electrons. So let's go ahead and start off with identifying our element. The way that we're going to identify our element is by adding the superscripts to determine the number of electrons. So we have two plus two plus three equals seven electrons. Now our periodic table are atomic number tells us the number of protons and in a neutral atom, r number of protons and electrons are going to equal each other. So the atomic number seven on our periodic table corresponds to the element nitrogen and nitrogen has the symbol end. So we just identified our element. Now we're going to identify the number of unpaid electrons. And in order to do this, we're going to need to fill in our orbital's and we can go ahead and do that by recalling our sub shells and the maximum number of electrons they can hold. So our s sub shell can hold a maximum of two electrons are p sub shell. You can hold a maximum of six electrons are D. Sub shell can hold a maximum of 10 electrons and are F sub shell can hold a maximum of 14 electrons. So in terms of orbital's remember our orbital's can hold a maximum of two. So that means our s sub shell has one orbital R p sub shell has three orbital's. Okay, Our D sub shell has five orbital's And our f sub shell has six orbital's. So we're going to fill in these orbital's to see how many unpaid electrons we have. Okay, and two things we need to remember when filling in. Our orbital's is the off ball principle which tells us to totally fill in the lowest energy orbital first. And huns rule we're going to first half fill before we totally fill. So let's look at our electron configuration. So we have to s sub shells here. Alright, so I'll go ahead and draw in another sub shell for S. And we said our S sub shell can hold a maximum of two electrons. So our first s sub shell has two electrons. So it's totally full. And our second s sub shell also has two electrons. So it's totally full. Moving on, we have a p sub shell that has three electrons. So we'll go ahead and fill in and remember we're doing huns rule you fill every seat before doubling up. So we have three electrons. Alright, so these this p sub shell is not completely full. So we have three UNP aired electrons. Alright, so this is the answer to the second part. Our element identified is nitrogen and we have three unpaid electrons. That's the end of this problem. I hope this was helpful

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