in this video I will show you how to name calent compounds calent compounds are also called molecules and they consist of non-metals only that means that a calent compound or molecule cannot have Metals here are some examples of coent compounds H2O consists of two non-metals the hydrogen nonmetal and oxygen nonmetal cl2 again two nonmetals and cl two consists of two non-metals that are the same and they're coal bonded to each other there are total of seven datomic elements which you have to memorize what are these elements the list the list includes hydrogen nitrogen oxygen Florine chlorine bromine and iodine these are elements that in nature prefer to exist as a pair or coupled to each other as opposed to single atoms this means that you'll never encounter in nature a single oxygen atom single oxygen atoms only exist in the form of radicals but a neutral oxygen atom is impossible to see the oxygen that we breathe in in the air is in this form it's diatomic O2 if you're asked to uh if you're asked to write the formula for an element you have to figure out if the element is diatomic or monoatomic in this exercise I'm showing you the difference between monoatomic elements and diatomic elements lithium is not on this list this is a monoatomic element and the formula is Li oxygen is on this list and its formula is O2 it's diatomic sodium is monoatomic just na iodine is diatomic right here formula I2 and silver is mon atomic element some Co valent compounds are so common that it's more practical to use their common name the three that you need to memorize are H2O common name is water NH3 it's common name is ammonia and CH4 its common name is methane all other compounds when you're asked to name them we will use the following rules that I'll discuss next these are I pack rules so let's talk about naming of calent compounds in this class we will consider naming of binary calent compounds that means that these are compounds that consist of two non-metals only you could have Co valent compounds that have three non-metals three different non-metals or four different nonmetals you don't need to know how to name them be able to name only coent compounds that consist of two different non-metals fix mono so we omit mono for the for the first nonmetal but we have to use it for the second nonmetal an example where we omit mono for the first nonmetal CO2 there's one carbon and two oxygens the first nonmetal is carbon we don't write this as monocarbon even though there's only one because we don't use mono on the first nonmetal and there's two oxygens this is the second nonmetal that's why we have to use the prefix d carbon di oxide Co on the other hand is carbon we don't use the prefix mono for the first nonmetal but we have to use mono for the second non-metal monooxide if you have o sorry monooxide if you have two vowels next to each other o o or AO you have to remove the first vowel so instead of carbon monooxide I get rid of the first vowel and this turn into monoxide sf4 is silicon and there's four flines Tetra fluoride p2o5 is D phosphorus pentoxide instead of pent oxide we remove the first vowel and this becomes pentoxide s O3 sulfur trioxide another thing to keep in mind when you're naming calent compounds or molecules is that we do not reduce the subscript in the formula you have to keep the subscripts this is different from what we did with ionic compounds with I in ionic compounds you have to reduce the subscripts to the lowest possible whole number ratio and I want to show you a specific example the formula H2O2 this is a equalent compound this formula shows the molecule hydrogen peroxide you're not allowed to reduce the subscripts you might be tempted to reduce the subscripts and you end up with ho which doesn't exist a ho o1 minus is the hydroxide anion but ho is not a neutral molecule H2O exists that's water um this is a calent compound again we do not reduce the subscripts in the formula in calent compounds but in ionic compounds we have to reduce the subscripts na2 cl2 this is coal ionic because there's a metal and a non-metal once we reduce these subscripts we end up with NAC which is uh sodium chloride that's an ionic compound that's the correct formula for sodium chloride and also when you're at when you're given a name of a coent compound and you're asked to come up with the formula please do not look at charges the charges are not going to make any sense to you because both of the non-metals will carry negative charges so instead look at the prefixes the prefixes will guide you to the correct formula in this NE exercise this next exercise I have a mixture of ionic and calent compounds and I've labeled I for Ionic and C for calent to show you how for the ionic compound we use charges for calent compounds we just use prefixes F3 N2 this is an ionic compound that contains a transition metal that forms two different charges and you have to figure out the charge on iron if we do the reverse crisscross method we see that iron carries a two plus charge and the name of this compound will be either iron 2 nitride or feros nitride the second compound is coent it consists of two non-metals list the first nonmetal which is nitrogen and the second nonmetal has uh subscript of three and we have to use the prefix Tri fluoride the third compound is ionic this is a main group element Potassium is not a transition metal so the name is just pottassium oxide not di potassium oxide we don't use prefixes with ionic compounds only with calent compounds in the last compound is also calent we have to use prefixes D for two D chlorine and for oxygen we have to use monoxide because there's only one and go ahead and do the last exercise on your own this shows you the difference between ionic calent compounds and just ions