Which of the following are ionic, and which are molecular? (a) PF₅

Video transcript

Hey everyone in this example, we need to determine whether the given compounds are ionic or molecular compounds. We're going to begin by defining what each of these terms represent. So for ionic compounds, we want to recall that, that's describing the transfer of electrons between two species. Either a metal or poly atomic ion and a non metal or poly atomic ion. Next we have molecular or covalin compounds and that is describing the sharing of electrons Between two nonmetal species. Our next step is to recognize the locations of where non metals and metals are located at on our periodic tables. So beginning with hydrogen and helium, we want to recall that these are considered non metals and then there's a staircase separation that begins at group three A. On our periodic tables where we have our meta Lloyd's and that's going to begin with boron, silicon arsenic to lori. Um And then we have a 17 beneath to Laurie um which is considered a non metal. That's why it's colored in blue because anything to the right of the staircase is going to be considered a nonmetal. We also have a few more metal Lloyd's. We have next to our arsenic uranium and we also have antimony next to to lori. Um beneath antimony. We have polonium, which I'm coloring in pink and that is due to the fact that anything to the left of this staircase is considered a metal. So now that we have our locations defined. Let's go ahead and begin the first example. So our first compound is silver oxide. So our first step is to analyze the atoms within this compound beginning with our silver, we have two atoms of silver in this compound. We want to recall where the location for silver is on our periodic tables and we see that it's located in the transition metal section of our periodic table. So before we can write out what charge as an ion silver has, we want to also analyze the other atom that it's bonded to in this compound. So that's going to be the oxygen here. So we want to recall where oxygen is located on our periodic tables and we recall that oxygen is in Group six A. On our periodic table. We want to recall that Adams in Group six A. Have a minus two charge. So that gives us the 02 minus an ion. And so that allows us to conclude that therefore we have the silver two plus catalon. And we know that because overall silver oxide is a neutral compound. And so again, silver is our metal oxygen because it's in group six a is our non metal. And so because we have the nonmetal here bonded to the metal silver, we also have the transfer of the two electrons from our oxygen being made to our silver. That is missing two electrons. And so this we can say, is going to be an ionic compound based on these combinations. And so this will complete our final answer for the first example silver oxide, we can now move on to example two where we have phosphorous tri chloride. So looking at the first atom in phosphorous tri chloride, that's going to be phosphorus based on its location on the periodic table. We see phosphorus is in Group five A. On the periodic table. We want to recall that atoms in Group five A. Will have a three minus charge. So that will give us the P three minus an ion based on its location, it's going to be considered a nonmetal. Moving on to the next atom in this compound, we have three atoms of chlorine. We want to recall that chlorine is in Group Seven A. On the periodic table which will be considered Um a an ion with a -1 charge due to it being in group seven a. And again this is also a non metal. So here we have the combination of a non metal and a nonmetal. We have the one electron from our chlorine being shared with the phosphorus here and then the three electrons from our phosphorus being shared with the chlorine, which is why we have the formula PCL three for phosphorous tri chloride. And so based on this combination, non metal and non metal, we can say that therefore this is going to be a molecular compound. And so this completes our final answer for example, to phosphorous tri chloride. So moving on to example three where we have carbon dioxide again, we want to analyze carbon first. So we want to recall that carbon is in Group four A. On the periodic table. We recall that atoms in Group four A. Will have a plus four or minus four charge. In the case of carbon, it's going to be C plus four for four plus and based on its location it's going to be considered a nonmetal. Moving on to our oxygen atom, We want to recall again, oxygen is in Group six A on our periodic tables. And so that's going to give us the 02 minus an ion, which again is going to be considered a non metal. So again we have two non metals bonded to one another. We have two electrons from our oxygen that are being shared with our carbon here, which is missing for electrons. And so overall that simplifies the formula too, since two is divisible into four As well as into itself. And so this simplifies to carbon dioxide co two. So we can therefore verify that this is also going to be a molecular or covalin compound. And so this completes our answer for the third example, carbon dioxide. So now we can move on to the fourth example which is our calcium sulfide. So looking at the first atom in this compound, we have calcium. We want to recall that based on its location on the periodic table, calcium is in group two a on the periodic table. We recall that Adams and group to a have a plus two charge that gives us the C. A. Two plus carry on. And based on its location, it's going to be considered a medal. Next we want to look at our sulfur atom. So based on sulfur is location on the periodic table. We see that sulfur is in group six A. On the periodic table. And recall again, Adams in group six A have a minus two charge. So that gives us the S two minus sulfide an ion. Again, this is going to be a nonmetal. So here we have the combination of our calcium metal bonded to our sulfur nonmetal. We have our two electrons from our sulfur being transferred to our two missing electrons from our calcium and that is giving us our neutral compound calcium sulfide. And so therefore because we have this combination of metal and non metal the transfer of electrons, this is going to therefore be an ionic compound. And so this will actually complete this example for calcium sulfide as our final answer. So I hope that everything be reviewed was clear. If you have any questions, please leave them down below and I will see everyone in the next practice video