Understanding Ionic Bonding and Compounds

All right, so we're going to talk about ionic bonding. So here, I love this picture. This is one of my favorite examples of how ionic compounds are different than the elements that they are composed of. So if I look at this first picture here, this is solid sodium. So it is in group 1A. It's metallic. It's soft. It's malleable, it's ductile, it conducts electricity, and it's highly reactive with water. Right? All right. And then the second picture, this is chlorine gas. Remember, chlorine is a diatomic element, and it has this kind of yellowish green tint to it as chlorine gas. Again, very poisonous if we were going to ingest chlorine gas. So solid sodium on its own is poisonous. Chlorine gas on its own is poisonous. But when those two elements combine and create an ionic... bond with each other and form sodium chloride. Now you all know sodium chloride, right? And this is a solid at room temperature. That's your table salt, right? And we put this on our food and we eat this. And obviously in huge quantities, it's going to be dangerous for us, but in small quantities, it's not. Right? So it's kind of cool. I love this idea that here we have these elements that can combine to make something so different and unique, which is our sodium chlorine. All right, so how does ionic bonding work? So it's not solid sodium and chlorine gas necessarily that are coming together to attach to each other. Instead, we have sodium ion and chloride ion. And those two ions come together and the plus and minus are attracted to each other by what we call electrostatic attractive forces. So that's kind of like our main definition of ionic bonding, where we have this electrostatic attractive forces between oppositely charged ions. So we're using Coulomb's law. So Coulomb's law states that opposites attract and same charges repel. So here we have opposite charges. You have a plus and a minus. And they're going to be attracted to each other, creating this electrostatic attractive force. And those oppositely charged ions create what we call the ionic bond. And so this picture here of an ionic crystal structure, so this is a crystal lattice structure, and this is an example of what sodium chloride would look like, is where you have millions of oppositely charged ions. attracted to each other. So just one little part of it is NaCl, right? And it's all of these NaCl ions in this crystalline structure, but one formula unit would be NaCl, okay? does this occur? So we're going to look at this closely and I'm going to go to my notes to do that. So let's look at sodium from the periodic table. It has an electron configuration of 1s2, 2s2, 2p6, 3s1, right? So it has that one valence electron. So all of this makes up the noble gas, neon, with a 10 core electrons. And this one here is our one valence electron. And this is again for solid sodium, not the ion. So when this loses one electron, minus one electron, it's the outermost electron that it's going to lose. So it's this electron here that gets lost. So when we make the sodium ion, it becomes positively charged. And the electron configuration for sodium ion is 1s2 2s2 2p6. And we say that is isoelectronic to neon. Now remember from our last chapter, it doesn't actually physically become neon. Isoelectronic just means same number of electrons. It doesn't mean it actually becomes neon. It does not become a noble gas. It is sodium ion. It still has some properties of sodium. It is just the ion form. So we're going to name this the name of the metal and then add the word ion to it. We don't use Roman numerals when we name sodium ion to indicate the charge because sodium ion can only form one type of ion. It loses that one electron from the valence. We lose that one electron from the valence. And then once you've lost that one electron, these core electrons are held in tight. And it's a lot of energy to try to remove that. Remember with ionization energy, that was a lot of energy to try to remove the second and third valence electron for sodium. So we can only lose that one valence electron and then it becomes sodium ion under normal circumstances. Okay, so that's how we make sodium ion. So now let's look at chlorine. Let's look at its growth. state neutral atom. electron configuration first. So we have 1s2, 2s2, 2p6. And remember what I'm doing, I'm just going back to my periodic table real quick, is I'm just going to cross my periodic table and going through the elements until it takes me to chlorine. So 1s2, 2s2, 2p6, 3s2, 3p, 1, 2, 3, 4, 5 to get to chlorine. Remember chlorine is element number 17. So to make sure we're correct, we're adding up our valence electrons. So 2 and 2 and 6 is 10, 2 and 5 is 17, so we have our 17 electrons. Okay, our core electrons, those are the ones that are involved, those are the ones that are tightly held into the nucleus. So from neon, those 10 core electrons, and then our valence electrons are the outermost. So for chlorine, we have 7 valence electrons, so VE for valence electrons. Remember, that corresponds to the group number as well. It's in group 7A, which is our halogens. So we have 5 and 2 giving us our 7 valence electrons. So that's what I'm adding up is the electrons in the superscript position, right? Okay, so how does it become an ion? So we're kind of looking at the 3P. And we're looking at the electrons. So we've got five. So one, two, three, four, five. And I could put the three S here too if we wanted to. So we're looking at our valence, right? And so for chlorine, we have this empty position here. And so instead of losing, how would it have to lose to become stable? It would have to go backwards way too many to get to neon. That's a lot of electrons. That's seven, right? So instead of losing electrons, it's more likely to gain one electron here to form an ion. So we're going to say plus one electron. And where does that get that electron from? What do you think? Yeah, it comes from the one that sodium lost, right? So we lost an electron there. Oops. And then chlorine is gaining an electron here. So the electron is transferred. And so chlorine gets a negative charge. And we go down to having this electron configuration of 1s2, 2s2, 2p6. 3s2 and now we gained one and now we have 3p6. Right? Because we gained one. So it fills up that P, creates a stable ion, a stable isoelectronic structure. And this becomes isoelectronic. Let's look at the periodic table and let us help us with that. Yeah, argon, right? Nice. So isoelectronic to argon. So now it has the same number of valence electrons as argon, or same number of electrons as argon. Okay, so why is it minus? Because it gained an electron, right? So if I look at sodium, so I'm going to change my color here to look at this. If I look at sodium, sodium is element number 11, and we have 11 protons. And when it becomes Na+, it now has 10 electrons. So if we look at that, that's a net of a plus one charge. with 11 protons and 10 electrons. If I look at chlorine as an ion, and we'll talk about how we name that in a second, it has 17 protons. By gaining an electron, it becomes 18 electrons. So if I look at that net, that's a minus one. So that's why it's chlorine has a minus one charge. So the way we name this is we call this chloride. ion. Now saying ide and ion is kind of redundant. Having that ide ending does mean it's the ion form of chlorine, but we can just add that in right now just to help us with our notes, right? So we are changing the ending of our nonmetal to ide when it becomes a negative ion. So let's kind of review our ion formation. Metals tend to lose electrons to form positively charged ions, and we call those cations. And nonmetals tend to gain electrons to form. negatively charged ions, and we call those anions. Okay, so metals tend to lose electrons, they form positively charged ions, and they're called cations. Nonmetals gain electrons, they form negatively charged ions, and we call them anions. Okay. So that might be something you put on a flashcard. So you put a flashcard for metals, a flashcard for nonmetals, and write these two definitions down along with a definition of an ionic bond. So remember, an ionic bond is an electrostatic attractive force between op. oppositely charged ions. An ionic bond formation is based on electron configurations and losing or gaining the valence electrons depending on whether it's a metal or non-metal. Okay, so let's do an example. I'm going to ask you about an element and you're going to tell me what kind of ion it's going to form. So let's start with magnesium. What type of element is magnesium? Is it a metal, a semi-metal, or a non-metal? It's a metal. And what do we say about metals? Yeah, they lose electrons. And when they lose electrons, they form negative ions. And when they lose electrons, they form positive ions. Excellent. So how many is it going to lose? Well, look at its position in the periodic table. It is in group 2A. So it needs to lose two valence electrons to go backwards to the previous noble gas and become isoelectronic to neon. So it's going to lose two electrons. And when it does that, it forms Mg with a 2 plus charge because it lost 2 electrons. It doesn't lose protons. Remember, protons tell you what element you have. You can't lose protons. That's only under nuclear reactions that you lose the protons. But in normal ionic formation, you're only losing electrons. So magnesium is losing its 2 valence electrons to form a plus 2 charge, and then it becomes isoelectronic to neon, right? So our charge is plus 2 for anything in group 2a. Next example, let's do oxygen. All right, is it a metal, a semi-metal, or a non-metal? Yeah, it's a non-metal. And what do we say about non-metals? Yeah, they gain electrons. So exactly how many electrons will oxygen gain? So it's all about its electron configuration. What kind of vacancy does it have in the 2p? So here's my 2p. We have one, two, three, four electrons. One, two, three, four. So what kind of vacancy do you see? Right here I see a vacancy. of 1, 2. So it's going to gain 2, moving it forward 1, 2 to the next noble gas. So oxygen forms oxide with a 2 minus charge. So it's 8 protons, and now we have 10 electrons when we gain the 2. Again, ion formation is based on electron configuration, and what we have available in the valence electrons, if there's leftover spots, it's going to fill them, or it's going to remove them to go backwards to the previous. previous noble gas and become isoelectronic with that. Especially if it's a main block element. So remember main block elements are those with the group A ending. Okay? All right, so wanna do one more example. What about aluminum? Is it a metal, a semi-metal, or a non-metal? It's actually a metal, right? Aluminum's a metal, so we'll write this over here. And what do we say about metals? Metals lose electrons, and it's going to lose its electrons to become isoelectronic with the noble gas, because it's a main block element. And that's not always true, but in this case it is true, right? So aluminum is going to lose one. It's going to go, let's see. It's going to lose one, two, three to go back to neon. So it's going to form a plus three ion. So our aluminum ion will have a 3 plus charge. Okay, so a rule of thumb, let's write this out. If you have a periodic table that's blank and you want to write on it so that you have notes, this is a good idea to grab that. You might want to pause the video so you can do that, and then we can make some notes on here. So in our group 1A, these form plus 1 ions. In group 2A, they're plus 2. 3A is plus 3. Now remember boron is a semi-metal, so your semi-metals won't do this. All right, so I'm going to color in the semi-metals for you so you can see them. They're not going to do the ion formation necessarily. So for the plus 3, we're talking about aluminum, gallium, indium, thallium, right? Okay, now noble gases don't necessarily tend to form ions, so we're going to start here with 7A. So fluorine. Adam's gonna gain one to go to neon. Chlorine's gonna gain one to go to argon. They're just trying to move towards being at noble gas, right? So that has to gain one, so this is gonna be a minus one charge. Oxygen has to gain one, two. Sulfur, one, two. Selenium, one, two. So these are gonna be a minus two charge. And the same is true for nitrogen. One, two, three. Phosphorus, one, two, three. So these are going to be a minus three charge. So it's all about location in the periodic table. I'm going to clean this up a little bit so you can see that metals are going to be positive ions and the group number helps us with that if it's a main group or a group A element. And non-metals are going to be negative ions and it has to do with how close they are to the upcoming noble gas. So I hope this was helpful and I hope it helps you understand a little bit about ion formation and how we create ions and then what our ionic bond is.

So it is in group 1A. It's metallic. It's soft. It's malleable, it's ductile, it conducts electricity, and it's highly reactive with water.

Right? All right. And then the second picture, this is chlorine gas.

Remember, chlorine is a diatomic element, and it has this kind of yellowish green tint to it as chlorine gas. Again, very poisonous if we were going to ingest chlorine gas. So solid sodium on its own is poisonous.

Chlorine gas on its own is poisonous. But when those two elements combine and create an ionic... bond with each other and form sodium chloride. Now you all know sodium chloride, right?

And this is a solid at room temperature. That's your table salt, right? And we put this on our food and we eat this. And obviously in huge quantities, it's going to be dangerous for us, but in small quantities, it's not. Right?

So it's kind of cool. I love this idea that here we have these elements that can combine to make something so different and unique, which is our sodium chlorine. All right, so how does ionic bonding work?

So it's not solid sodium and chlorine gas necessarily that are coming together to attach to each other. Instead, we have sodium ion and chloride ion. And those two ions come together and the plus and minus are attracted to each other by what we call electrostatic attractive forces.

So that's kind of like our main definition of ionic bonding, where we have this electrostatic attractive forces between oppositely charged ions. So we're using Coulomb's law. So Coulomb's law states that opposites attract and same charges repel.

So here we have opposite charges. You have a plus and a minus. And they're going to be attracted to each other, creating this electrostatic attractive force. And those oppositely charged ions create what we call the ionic bond. And so this picture here of an ionic crystal structure, so this is a crystal lattice structure, and this is an example of what sodium chloride would look like, is where you have millions of oppositely charged ions.

attracted to each other. So just one little part of it is NaCl, right? And it's all of these NaCl ions in this crystalline structure, but one formula unit would be NaCl, okay?

does this occur? So we're going to look at this closely and I'm going to go to my notes to do that. So let's look at sodium from the periodic table. It has an electron configuration of 1s2, 2s2, 2p6, 3s1, right? So it has that one valence electron.

So all of this makes up the noble gas, neon, with a 10 core electrons. And this one here is our one valence electron. And this is again for solid sodium, not the ion. So when this loses one electron, minus one electron, it's the outermost electron that it's going to lose. So it's this electron here that gets lost.

So when we make the sodium ion, it becomes positively charged. And the electron configuration for sodium ion is 1s2 2s2 2p6. And we say that is isoelectronic to neon. Now remember from our last chapter, it doesn't actually physically become neon. Isoelectronic just means same number of electrons.

It doesn't mean it actually becomes neon. It does not become a noble gas. It is sodium ion.

It still has some properties of sodium. It is just the ion form. So we're going to name this the name of the metal and then add the word ion to it. We don't use Roman numerals when we name sodium ion to indicate the charge because sodium ion can only form one type of ion. It loses that one electron from the valence.

We lose that one electron from the valence. And then once you've lost that one electron, these core electrons are held in tight. And it's a lot of energy to try to remove that.

Remember with ionization energy, that was a lot of energy to try to remove the second and third valence electron for sodium. So we can only lose that one valence electron and then it becomes sodium ion under normal circumstances. Okay, so that's how we make sodium ion. So now let's look at chlorine. Let's look at its growth.

state neutral atom. electron configuration first. So we have 1s2, 2s2, 2p6.

And remember what I'm doing, I'm just going back to my periodic table real quick, is I'm just going to cross my periodic table and going through the elements until it takes me to chlorine. So 1s2, 2s2, 2p6, 3s2, 3p, 1, 2, 3, 4, 5 to get to chlorine. Remember chlorine is element number 17. So to make sure we're correct, we're adding up our valence electrons.

So 2 and 2 and 6 is 10, 2 and 5 is 17, so we have our 17 electrons. Okay, our core electrons, those are the ones that are involved, those are the ones that are tightly held into the nucleus. So from neon, those 10 core electrons, and then our valence electrons are the outermost.

So for chlorine, we have 7 valence electrons, so VE for valence electrons. Remember, that corresponds to the group number as well. It's in group 7A, which is our halogens.

So we have 5 and 2 giving us our 7 valence electrons. So that's what I'm adding up is the electrons in the superscript position, right? Okay, so how does it become an ion? So we're kind of looking at the 3P.

And we're looking at the electrons. So we've got five. So one, two, three, four, five.

And I could put the three S here too if we wanted to. So we're looking at our valence, right? And so for chlorine, we have this empty position here. And so instead of losing, how would it have to lose to become stable? It would have to go backwards way too many to get to neon.

That's a lot of electrons. That's seven, right? So instead of losing electrons, it's more likely to gain one electron here to form an ion. So we're going to say plus one electron.

And where does that get that electron from? What do you think? Yeah, it comes from the one that sodium lost, right? So we lost an electron there.

Oops. And then chlorine is gaining an electron here. So the electron is transferred. And so chlorine gets a negative charge.

And we go down to having this electron configuration of 1s2, 2s2, 2p6. 3s2 and now we gained one and now we have 3p6. Right?

Because we gained one. So it fills up that P, creates a stable ion, a stable isoelectronic structure. And this becomes isoelectronic. Let's look at the periodic table and let us help us with that.

Yeah, argon, right? Nice. So isoelectronic to argon. So now it has the same number of valence electrons as argon, or same number of electrons as argon. Okay, so why is it minus?

Because it gained an electron, right? So if I look at sodium, so I'm going to change my color here to look at this. If I look at sodium, sodium is element number 11, and we have 11 protons. And when it becomes Na+, it now has 10 electrons. So if we look at that, that's a net of a plus one charge.

with 11 protons and 10 electrons. If I look at chlorine as an ion, and we'll talk about how we name that in a second, it has 17 protons. By gaining an electron, it becomes 18 electrons. So if I look at that net, that's a minus one. So that's why it's chlorine has a minus one charge.

So the way we name this is we call this chloride. ion. Now saying ide and ion is kind of redundant.

Having that ide ending does mean it's the ion form of chlorine, but we can just add that in right now just to help us with our notes, right? So we are changing the ending of our nonmetal to ide when it becomes a negative ion. So let's kind of review our ion formation.

Metals tend to lose electrons to form positively charged ions, and we call those cations. And nonmetals tend to gain electrons to form. negatively charged ions, and we call those anions. Okay, so metals tend to lose electrons, they form positively charged ions, and they're called cations. Nonmetals gain electrons, they form negatively charged ions, and we call them anions.

Okay. So that might be something you put on a flashcard. So you put a flashcard for metals, a flashcard for nonmetals, and write these two definitions down along with a definition of an ionic bond. So remember, an ionic bond is an electrostatic attractive force between op. oppositely charged ions. An ionic bond formation is based on electron configurations and losing or gaining the valence electrons depending on whether it's a metal or non-metal.

Okay, so let's do an example. I'm going to ask you about an element and you're going to tell me what kind of ion it's going to form. So let's start with magnesium.

What type of element is magnesium? Is it a metal, a semi-metal, or a non-metal? It's a metal. And what do we say about metals?

Yeah, they lose electrons. And when they lose electrons, they form negative ions. And when they lose electrons, they form positive ions.

Excellent. So how many is it going to lose? Well, look at its position in the periodic table. It is in group 2A.

So it needs to lose two valence electrons to go backwards to the previous noble gas and become isoelectronic to neon. So it's going to lose two electrons. And when it does that, it forms Mg with a 2 plus charge because it lost 2 electrons. It doesn't lose protons.

Remember, protons tell you what element you have. You can't lose protons. That's only under nuclear reactions that you lose the protons. But in normal ionic formation, you're only losing electrons. So magnesium is losing its 2 valence electrons to form a plus 2 charge, and then it becomes isoelectronic to neon, right?

So our charge is plus 2 for anything in group 2a. Next example, let's do oxygen. All right, is it a metal, a semi-metal, or a non-metal?

Yeah, it's a non-metal. And what do we say about non-metals? Yeah, they gain electrons.

So exactly how many electrons will oxygen gain? So it's all about its electron configuration. What kind of vacancy does it have in the 2p? So here's my 2p.

We have one, two, three, four electrons. One, two, three, four. So what kind of vacancy do you see? Right here I see a vacancy. of 1, 2. So it's going to gain 2, moving it forward 1, 2 to the next noble gas.

So oxygen forms oxide with a 2 minus charge. So it's 8 protons, and now we have 10 electrons when we gain the 2. Again, ion formation is based on electron configuration, and what we have available in the valence electrons, if there's leftover spots, it's going to fill them, or it's going to remove them to go backwards to the previous. previous noble gas and become isoelectronic with that. Especially if it's a main block element.

So remember main block elements are those with the group A ending. Okay? All right, so wanna do one more example. What about aluminum?

Is it a metal, a semi-metal, or a non-metal? It's actually a metal, right? Aluminum's a metal, so we'll write this over here.

And what do we say about metals? Metals lose electrons, and it's going to lose its electrons to become isoelectronic with the noble gas, because it's a main block element. And that's not always true, but in this case it is true, right? So aluminum is going to lose one.

It's going to go, let's see. It's going to lose one, two, three to go back to neon. So it's going to form a plus three ion.

So our aluminum ion will have a 3 plus charge. Okay, so a rule of thumb, let's write this out. If you have a periodic table that's blank and you want to write on it so that you have notes, this is a good idea to grab that. You might want to pause the video so you can do that, and then we can make some notes on here.

So in our group 1A, these form plus 1 ions. In group 2A, they're plus 2. 3A is plus 3. Now remember boron is a semi-metal, so your semi-metals won't do this. All right, so I'm going to color in the semi-metals for you so you can see them. They're not going to do the ion formation necessarily. So for the plus 3, we're talking about aluminum, gallium, indium, thallium, right?

Okay, now noble gases don't necessarily tend to form ions, so we're going to start here with 7A. So fluorine. Adam's gonna gain one to go to neon.

Chlorine's gonna gain one to go to argon. They're just trying to move towards being at noble gas, right? So that has to gain one, so this is gonna be a minus one charge. Oxygen has to gain one, two.

Sulfur, one, two. Selenium, one, two. So these are gonna be a minus two charge.

And the same is true for nitrogen. One, two, three. Phosphorus, one, two, three. So these are going to be a minus three charge. So it's all about location in the periodic table.

I'm going to clean this up a little bit so you can see that metals are going to be positive ions and the group number helps us with that if it's a main group or a group A element. And non-metals are going to be negative ions and it has to do with how close they are to the upcoming noble gas. So I hope this was helpful and I hope it helps you understand a little bit about ion formation and how we create ions and then what our ionic bond is.

Transcript for:Understanding Ionic Bonding and Compounds

Transcript for:
Understanding Ionic Bonding and Compounds