welcome to getchemistryhelp decom my name is Dr Kent and our lesson is going to be on identifying ionic versus molecular compounds now as we'll see in our future lessons on naming compounds it's vitally important that we can tell the difference because the way that an ionic compound is named is completely different from the way a molecular compound is named so just real quickly here I'll just show you how to tell the difference now ionic compounds are just what they sound like they are compounds composed of ions so they're going to have one or more cat ions paired up with one or more anion now as you might recall cations ions are ions that have a positive charge while annion are ions that have a negative charge now typically but not always but 99.9% of the time ionic compounds are easy to identify because the cat that's present is going to be a metal now here below I put a copy of the periodic table for us and there's a little staircase that kind of goes along here but it's kind of hard to see so I'll kind of fill it in for us now on the left side of the staircase this is where the metals live so over here these are going to be metals and on the right side of the staircase these are what are called the non-metals and right along the staircase right along here these are called the semimetals or the metalloids so if you see one of these elements on the left side you can be sure that it's going to be an ionic compound so any of these elements live right along here anywhere along here if one of these elements is present in the compound it's going to be an ionic compound now notice though just real quickly hydrogen is technically on the left side but hydrogen is a non-metal we could have written it right over here in the non-metal part because I think you would agree that h is a gas and it has properties that are more similar to a non-metal than it does Metals which tend to be solids shiny good conductors Etc so for example let's say we had sodium and chlorine together in a compound well sodium lives right here it's a metal so that must be an ionic compound Let's see we had iron combined with bromine in a compound okay so if we find iron it lives right here so that's a metal so that would be an ionic compound uh let's say we had um silver combined with sulfur where silver live oh it's right here of course that's a metal so if it's got a metal it's going to be an ionic compound now molecular compounds or what are called Cove valent compounds they are formed of just non-metals so again the non-metals live up here in this top right kind of quadrant plus hydrogen so if all of the elements that are present in that compound come from this area of the periodic table the non-metals then you can be sure it's a molecular compound for example water is probably one we all know water is two nonmetals hydrogen and oxygen are both non-metals so that would be a calent compound or molecular compound how about carbon dioxide well carbon and oxygen here's carbon here's oxygen so those are both non Metals how about a compound that's called phosphorus hexol fluide well phosphorus and Florine they both live on the non-metal sides so these would all be molecular or Cove valent compounds okay so just real quickly here we'll go through some examples and see if we can pick out if these are ionic or molecular compounds so potassium and chlorine so let's find both the elements well here's potassium here's chlorine so it's got a metal and a non-metal so because it has a metal we can be sure it must be an ionic compound how about nitrogen and two oxygen or what's called nitrogen dioxide well nitrogen okay that lives right here oxygen that lives right here so these are both non-metals so this compound must be molecular how about hydrogen and sulfur well here's hydrogen here's sulfur again hydrogen is on the left side but remember technically we could have written it over here with the other non-metals so they're both non-metals so this would be a molecular compound how about iron sulfur and oxygen together in a compound well here's iron here's sulfur and here's oxygen so iron is a metal so therefore it must be an ionic compound okay well how would you figure out this one carbon hydrogen and oxygen so we look and we find here's carbon here's hydrogen and here's oxygen so what do you think is it ionic or molecular well carbon hydrogen and oxygen are all non-metals so it must be molecular and one last one lead chlorine and oxygen together so here's lead here's chlorine and here's oxygen remember our staircas case runs right along here so lead is on the left side so lead is a metal which means it must be an ionic compound well I hope you enjoyed this quick lesson be sure and click Down Below on the Subscribe button so you can be notified as soon as new videos are posted and we'll see you next time at getchemistryhelp tocom thank you