Learning target 2.19, I can name covalent compounds. Similar but different and the difference is huge. So whenever you see a compound and you have to name it, please, please, please make sure it's covalent or ionic before you try and name it. Okay, let's go over the steps for a covalent compound which is non-metal. And a non-metal. Okay, step one. Name the less electro-negative element first. Okay. Name less electro-negative element first. So how do you know if something is not very electro-negative? Look at the periodic table. This is high VN. This is low EN. Okay. Name the one that's less electro-negative first. Right. Then name the more electro-negative. A second. Okay. Step three. Change the ending of the second one. And good. So this part is very similar to the ionic compound except since there's no metal, you don't name the metal first. You name the one that's less electro-negative first. Okay. Now, let's go ahead and look at the difference. So your step four is the difference part. Okay. So you're going to use a prefix to describe how many of each atom are in the molecule. There's an exception to this because it's chemistry. And of course we like to make your light heart. The exception is if the first atom has a subscript of one, we don't use mono. Okay. Exception. If first element has subscript of one, we don't use mono. Okay. So what are the prefixes that you're allowed to use? Okay. Let's go over them. The Greek. So mono is one. Die is two. TRI is three. Tetra is four. Penta is five. Hexa. The hexagon is six. Penta is seven. Opta is eight. Nana or Nona is nine. Deca is ten. Chances are you want you to go past these. These are the prefixes that go in front of your covalent anion or covalent, sorry, electro-negative elements. Okay. So let's go ahead and use these four steps to name a couple of elements, sorry, a couple of compounds. So literally a couple. Here are two that we're going to work on. We're going to work on N204 and SIF4. So first I need to double check to make sure that it is a covalent compound. Nitrogen is a non-metal. Oxygen is also non-metal. So this is covalent. We're good to go. So step one was to name the less electro-negative element first. Happens that nitrogen is further to the left. The oxygen, so we're going to name nitrogen first. Let's go ahead and write down nitrogen. Step one. Step two. Write down oxygen. SIF3. Change that to oxide. Good. Right. So let me go ahead and write that out. So far we have nitrogen and oxide. Okay. Now support is the different one, and that's where you use the prefixes. What's the prefix for two? What's the prefix for four? Okay. So then you put it in front, because if it's a prefix, it will go in front. So the prefix of dye goes in front of nitrogen. This signifies that there are two nitrogen. The prefix of tetra goes in front of oxide. To signify that there's four oxygen atoms. You might also see tetroxide, because it's a little weird to say to have two vowels next to each other. Right. So the answer is your final answer is dye nitrogen tetroxide. Okay. Let's go ahead and try silicon and F. So silicon is non-metal. Flora is non-metal. So we can use this naming method. Number one. Write down the least or the less electron negative one, which is silicon. Second step. Write down the one that is more electron negative. That's fluorine. Step three. Change the ending to fluoride. And step four. Let's look at the prefixes. Okay. The subscript of SI is one. Right. Because there's nothing there. It's the invisible one. Do I say that this is monosilicon? Sorry. That's my dog. Do we say that this is monosilicon? The answer is no. Right. Because if you go back to the exception, which I will show you here, the exception is if the first element has a subscript of one, we don't use mono. I apologize for my dog. So SI is good to go. Don't worry about that. And four is in front of the F. So four is tetra again. They're really good guard dog. Which I see nuts. So then there's nothing here. And this is tetra fluoride. So if you go on tetra fluoride, is the name of the covalent compound.