 Okay, so let's try this one. It says, for the pictured atom, draw the full electron configuration. Sorry. Draw the condensed electron configuration. Calculate the number of inner electrons and calculate the effective nuclear charge for this atom. Okay? So, first we need to do draw the electron configuration. So, what would it be for chlorine? 1s2, 2s2, 2p6, 3s2, 3p1, 2, 3, 4, 5. Right? Yes. So, if you're wondering, you should be able to count all of these numbers and they should equal the atomic number. Okay? So, if I wanted to do the noble gas electron configuration, what would that be? So, remember, I take the noble gas that's the one before chlorine. So, in this case, it would be neon. And then I write everything after neon. Right? So, neon is up to 2p6. Isn't that the case? If you don't know or you think that's crazy, you better look at the periodic table. Okay? So, it's got that. Okay? So, that's the condensed or noble gas or abbreviated electron configuration. Okay, they wanted us now to figure out the number of inner electrons. So, remember how I taught you how to do that? So, it's the number of electrons that the noble gas contains plus the number of filled D plus filled Fs. And so, noble gas, what's the noble gas before it? Neon. Right? It contains how many electrons? Ten. Ten. Very good. And do we have any filled Ds? Zero. Zero filled Fs? Zero. So, the number of inner electrons is ten electrons. Okay? Does that make sense? So, the other ones are the valence electrons. Okay? So, if you wanted to say how many valence electrons, it would be seven valence electrons. Right? Okay? And so, the effective nuclear charge, remember, what did we say? It was the atomic number minus the number of inner electrons. So, do we have the atomic number? Yeah, we get that for the periodic table. Seventeen minus inner electrons ten. So, the overall nuclear, effective nuclear charge is plus seven. Okay? So, what you see is that the inner electrons actually shield the nucleus from exhibiting its full nuclear charge, if that makes sense. Okay? The valence electrons don't do anything. Any questions before we kill this one? Questions? Questions? What was that? Yeah. So, what are we seeing here? Is that the inner electrons are taking away charge from the overall nuclear charge, right? Because the overall nuclear charge of chlorine is set plus seventeen, right? But the effective nuclear charge is only plus seven, right? So, the inner electrons, which is ten, are shielding the nucleus of the chlorine to only, instead of be projecting a plus seventeen charge, it's only projecting a plus seven charge. Does that make sense? Does that make sense, everyone? So, the inner electrons shield, the valence electrons do not shield. That's the overall picture what we want you to take from this. Okay? So, any other questions? That was a good question. Any other questions? Okay, wonderful.