In this video, we're going to look at the different types of chemical bonds. By the end of this module, you should be able to identify the different types of bonds in substances. So when we look at substances, whether we're talking about molecular elements, molecular compounds, or ionic compounds, we know there's something holding those atoms together. And so, when we talk about compounds, we're worried about what types of bonds are holding those atoms together. And there's just basically some attraction between those atoms. And where this attraction happens is between the protons and the electrons. Remember that the protons in the nuclei are positively charged. The electrons around the nuclei are negatively charged. So, the protons on one atom have some attracted to the electrons on the other, and vice versa. And this is where we can get the formation of chemical bonds. So, when we look at the periodic table of the elements, we see lots of information included here. The main thing we're worried about is the different types of elements that we have. Now, if we look on the left side of the periodic table, to the left of this kind of red line here, those elements are our metals except for hydrogen, which is a nonmetal. Hydrogen has kind of an odd location on the periodic table because it has a variety of properties that means it doesn't quite fit in very well anywhere. And so, we see all of these elements are our metals. And over here on the right side, so these are metals. And on the right side, we have our nonmetals. And the type of element we have is going to be a major predictor in the type of bond that will form. Now, just like many other things in chemistry, there are exceptions to this rule, but we're going to be worried about what happens the majority of the time. So, we have our nonmetals and our metals. When we look at our nonmetals, what we're going to find is that there are a lot of different ways that these atoms can bond to one another. And especially with carbon, we have many options because we can make chains of carbon atoms. We can make branches off of those chains. We can add a few other elements. And this is the whole class of organic chemistry, where we have lots of different ways to arrange just a few different types of atoms. But the more we have, the more options we have for how to arrange them. When we look at metals bonding with nonmetals that we get in ionic compounds, what we see is that we have many fewer options for how those elements are going to combine. And that's what also lets us predict what the formula is going to be for that compound. If I know I just have nitrogen and oxygen in a compound, I can't easily predict what it's going to form. If I know I only have potassium and bromine, I know exactly what the formula is for that compound. And those differences in knowing what the compound's formula is going to be are going to be reflected in our rules for nomenclature when we start looking at the names of compounds. There are three different types of bonding we can look at, metallic, ionic, and covalent. Metallic bonding is between two or more metal atoms, and we're not going to explore that further here. It goes a little beyond the depth of this course, but know that we can have metallic bonding. Covalent bonding, on the other side, is between two or more non-metals. And in between, when we have a metal and a non-metal, we get ionic bonding happening. When we have ionic bonding, what we have are electrons being transferred between atoms, specifically between a metal and a non-metal atom. And what we find is that the metal is always going to be the electron donor. Right? It's going to give up an electron, and our non-metal, in this case chlorine, is going to be our electron acceptor. Right? So what we see is that we get a nice combination of sodium and chlorine. Sodium wants to give up one electron, chlorine wants to take one electron based on their electronic structure. And so, because sodium wants to get rid of that one electron, it will happily give it up. Chlorine wants to accept it and gets octet or have eight electrons around it, eight valence electrons around it. So it's going to accept that electron. What results is a positively-charged sodium ion, a negatively-charged chloride ion because now the chlorine has an extra electron. Sodium has lost an electron, so it has a positive charge. And now we have two species with opposite charges that are attracted to each other and are going to form this ionic compound. For covalent bonding, it's a little bit different. We still see that the electrons are involved. That's always going to be involved in our bonding. But now, instead of the transfer of electrons from one atom to the other, what we now see is the sharing of electrons between atoms. We still have atoms that have that same goal of getting an octet or eight electrons around them, except, of course, again, hydrogen, which doesn't want eight. It only wants two electrons around it. But we see that they're going to share electrons so that all of the atoms have enough electrons around them. And we see this happening in non-metal atoms. And so, they're able to share those electrons in different ways to form different compounds. So, the example we mentioned earlier about nitrogen and oxygen, it can form different compounds with different numbers of nitrogen and, and oxygen atoms because those electrons can be shared in a variety of ways. Let's look at an example where we identify the group that contains only substances with covalent bonds. So, if we're looking for covalent bonds, what we want to be involved are two or more nonmetals. When I look at something like sodium chloride, what I see is I have a metal and a nonmetal. This is going to form an ionic compound, and so it's going to have an ionic bond, not a covalent bond. When I look at CO2, two nonmetals, so we have covalent bonds there. H2, it's a molecule, but its still has a covalent bond because it's two nonmetal atoms. Carbon monoxide is nonmetals, two nonmetals, so we have covalent bonds, as are water and Cl2. When I look at this last group, I see that I have potassium and chlorine, which is an ionic bond because we have a metal and a nonmetal. Magnesium bromide, which, again, metal and a nonmetal, so it's an ionic bond. And sodium and oxygen, metal and a nonmetal, so we have an ionic bond. So, b is our best answer. In the next module, we're going to look at the chemical formulas. We've seen several of them, but now we're going to figure out what they mean and how we write them.
