01 - Introduction To Chemistry - Online Chemistry Course - Learn Chemistry & Solve Problems

hello and welcome to the chemistry tutor my name is Jason I'm going to be your teacher here during this course and what you're going to find is that during the entire DVD series where we talk about chemistry we're going to take every single topic from step by step chunks manageable chunks and we're going to build your knowledge and small little incremental measurable steps so that every step along the way you're going to be able to follow everything that's going on before you know it you'll be balancing chemical reactions and calculating the yield of a chemical reaction you know without any problems now will tell you that chemistry is one of the subjects that a lot of students really do have trouble with when we first begin you know when we start taking chemistry room to grow up a little bit we take that kind of class the reason is that almost every single problem that you are going to have in your chemistry class is going to be a word problem so a lot of people don't like word problems you have to read it and more than that you have to understand it that's really the challenge there the number one thing that students do wrong when they read a word problem read a chemistry problem is that they'll try to take the numbers in the problem and add them or subtract them or do something to them to try to get to the answer without really reading and seeing what the problem is really and truly asking you to do and that really is the key you have to read it you have to understand what is being asked and what you were given so that you can outline a logical path from start to finish and that's the kind of skill base that we're going to get when we do these problems in this class because all of the problems that we do here are going to also be word problems to give you that practice there now let me jump back a little bit chemistry is incredibly interesting it's one of the few branches of science that you can really study and whole and really feel like you have an everyday connection to it that's why I think it's so interesting you know I love and enjoy physics you know I have a degree in physics it's really neat but when you start getting into advanced physics you really lose the ability to visualize what's happening when you know when you have a lectric field or something in a room it's invisible you can't touch it you can't taste it you can't see it so it's very interesting I love that stuff but it's not very tangible a lot of times when you get into the advanced stuff but chemistry is something you can open up your kitchen open up your refrigerator and see things you know that were made chemically all around you so it's something that you come into everyday contact with you know the plastic that you use when you put it in a ziploc bag or a zippy bag or something and throw it in the freezer some kind of food that plastic is a long chain of atoms that are bonded together and someone designed that chemical to be strong to be plastic and pliable so we can move it to be temperature resistant it was engineered to serve a function and they built it they put it together and we use it everyday you know aluminum foil you know that thin sheet aluminum foil very very useful it's you know people go in the factories figure out how to extrude that aluminum figure out how to make it flat so that we can use it you know all the way to rocket science you know the most powerful shouldn't say the most powerful but one of the most powerful and energetic chemical reactions that there there are that there is is if you take hydrogen gas or liquid hydrogen if it's liquefied you know that's the same stuff the hydrogen is the same stuff that we put in the Hindenburg years ago but you know unfortunately burned and went up in flames but hydrogen and you take oxygen right and you put them together mix them together two very simple things off the periodic table you mix them in you ignite them and what do you produce water right but it's a very energetic reaction we also produce a lot of heat and that causes those gases to go really really fast right out the back of a rocket engine and that's you know one of the most powerful rocket fuels that we have so we go all the way to rocket science we can really understand how chemistry can boost a rocket into space all the way back down to your kitchen if you take you know some baking soda right off of the shelf and you take some ordinary vinegar right off the shelf and you put some baking soda in the kit in the cup you pour some vinegar right on top of it you don't have to light it you don't have to blow on it you don't have to cool it you don't have to heat it but just the act of pouring those two things together will cause a chemical reaction to happen to you know bubble up producing a gas and we'll talk all about that stuff a little bit later but I guess the point I'm trying to make is that chemistry really is all around you when you have a matchbook you strike a tip of that match that's a chemical that someone has designed and and tested and put on the tip of that match to serve a function plastic cars rubber it's everywhere and a lot of students have difficulty with this class but we're going to break down those barriers here now there's one final note that I'm going to tell you here as a sort of a piece of advice before we get started on this journey and that is that even though a lot of students have problems with chemistry there are two main reasons that we have these problems the first reason is because the definitions right the definitions that is the most important thing we really have to make sure we know we're talking about so when I tell you that I'm talking about a molecule you really think you understand what you know what the one I'm talking about everyone has their ideas you may have your own idea what a molecule is right now maybe you're correct maybe or not but we have to make sure we're on the same page definitions are key so that's really what this section is going to be is going to be a lot of definitions I'll try to make it a little interesting but basically you have to have the terminology now second thing is what I talked about before very very important when we read our problems not just to just kind of glance through picking out numbers that's not what we're doing we need to really read it and really understand it with that you'll know what to do the other thing I'll say is that when you're doing chemistry problems you know to be truthful most of the time you're just going to be adding subtracting multiplying and dividing right there's I don't want to say there aren't any any equations or formulas in chemistry because there there are but when you compare chemistry - maybe physics or something physics is chock-full of equations you have to understand the equations chemistry really don't have too many equations but you have a ton of concepts and we have to understand those concepts but you're not going to get any higher in the math more than addition subtraction multiplication and division most of the time so pat yourself on the back if you know how to add you're not a multiply divide subtract you're in pretty good shape but what we need to do together is build the logic so we're going to do that here all right so what is chemistry that's the number one thing we need to answer I think most people have a pretty good idea about what chemistry is but let's explore it together if I had to write a definition for chemistry and I had to keep it short and sweet my definition is the following it's the study of the composition and structure of matter and changes that occur in matter now one thing I'll say for everyone here listening is that when I write definitions and I try not to front-load all the lectures with definitions but we just have to do it in this case I'm going to generally write them down because it helps me articulate what we're saying it helped it forces me to read every word and I think it forces you to read every word so I could I could blast the screen here with a with a large definition that you have to kind of scan through but I think there's something gained in reading every word as it goes up on the board just like a regular classroom so that's what we're going to do chemistry is this definition pretty much fall should fall in line with what you probably have in your head it's the study of the composition and structure of matter and changes that occur in matter when we say changes that occur in matter we're talking mostly about chemical reactions that's mostly what we're talking about so we're going to spend a good chunk of time in the beginning of the class talking about what is you know an element how do you calculate how do you figure out how elements you join together and then once we understand that we're going to combine different things in a chemical reaction to form a new product hydrogen plus oxygen gives you water carbon plus oxygen gives you carbon dioxide or carbon monoxide how does all that come together how do we know what's going to be formed and how much of it will be formed if we put you know different amounts of chemicals together how much of the stuff is going to come out the other end that's really what we're trying to do in chemistry it's one of the most important things so I'm giving you a couple of examples but if I had to give you a couple of additional example examples what about wood when we burn it when wood burns right if we take a piece of wood and we put a match to it what happens well we get a lot of smoke and we get some heat right that is a chemical reaction oxygen in the air is combining with basically it's combining with the wood and everything else in the wood we get carbon dioxide and then of course the the particles that we see the smoke is just a little particles that after they've been burned floating up into the sky but we have carbon dioxide and a host of other things that come out of burning that's a chemical reaction what else do we have something may be it may be you may or may not have thought of as a chemical reaction what if we take iron and we watch it rust well what happens here is we have the iron reacts with the oxygen and what we get out of that is iron oxide now notice I'm not writing this down into a chemical reaction in terms of the elements combining and giving you a you know a chemical formula on the end we're going to get into all that stuff later right now we're just trying to build the concepts this is an example of the stuff that we're going to really study in chemistry you take something like iron you just let it sit in the atmosphere over time the oxygen will combine with that iron spontaneously it's just a natural process and out the other and you'll get what we call iron oxide which is rust which is oranges you know material the almost the entire surface of Mars is iron oxide so it's been oxidizing for a long time but if you take a piece of iron stick it outside five months later come back you'll see some kind of brownish reddish coloring on it that's a chemical reaction all right and we already talked about rocket fuel when we take hydrogen and oxygen we combine them together we get water of course we also get heat out of it because that's a that's a reaction that has heat involved in it also all right so that's just a general idea general overview of chemistry in general the kind of things that we're going to be looking at now obviously chemistry is a mathematical science so we're not just going to be writing words down we'll have elements and we'll have amounts and in terms of how much of things that we mix together and how much is produced and that's what we're going to be interested in calculating now in order to get anywhere else in our journey in chemistry we have to follow sort of a logical sequence some of the stuff I'm about to tell you you probably already know from second grade I'm pretty sure most of you already know that everything is made of atoms but what we need to do is start at the beginning maybe there's a nugget in there that you didn't quite know but no matter what we need to start at the beginning and make sure that you understand everything so that as we get to the end I'll build you up so that nothing will be left out so if you understand what an atom is you'll understand our first little guy right here what we have is the concept of and atom and for those of you who know what this is and maybe haven't revisited it in a long time we'll just talk about it here it's basically the smallest elemental and by the way there are a million definitions for an atom you could write down but this is mine smallest elemental unit in a sample of matter of matter all right so what are some examples of atoms there are things that you've heard of that you've played with that you've touched and even you've that you breathed what about the atom of oxygen all right the chemical symbol for oxygen is the letter O all right so that is an atom we also call it an element because I'm kind of alluding to a few things here that will concur here in a little bit but there's a periodic table of all of the elements that we know about and those elements are basically arranged so everything in the universe that we know about is made up of these elements which are just different kinds of atoms and they combine in different ways much like hydrogen is a gas this explosive oxygen is a gas colourless odourless but we breathe it we use it right you take those two things together it make em eclis react and form water now water doesn't look anything like hydrogen and water doesn't look anything like oxygen so when you combine these things together they form new substances whose properties are totally different from the basic things that they're made of so that's why we have so many different things around us that look totally different the plastic in a bag the rubber in a tire the glass in your house they're all made of atoms which are just combinations of different I should say they're they're they're made of different combinations of these atoms which are these elements that we have all around us so an example of an atom is the element oxygen chemical symbol oh how about nitrogen probably heard of this chemical symbol is and our atmosphere is made of mostly nitrogen believe it or not and about 20% oxygen so we have this stuff floating around you're breathing it right now what about carbon the chemical symbol for that is the element C we represent C for carbon in for nitrogen o for oxygen right carbon is you know in charcoal carbons in everything it's in your body it's in wood anything living carbon we're going to learn later is an incredibly versatile element it bonds in ways that that other elements don't and that that's why life is really built on carbon because it's really kind of unique and kind of cool what about iron we talked a little bit about iron what would be the chemical symbol of that you'd think the chemical symbol for iron would be I but it's not it's actually if you look on your periodic table it's F E and I'm kind of bringing this up because you'll see that a lot of times some of these elements the chemical symbol will be the same letter as the first or the letter as the as the first letter in the name but for some of them it's going to look totally different and that's because you have to understand a lot of the scientists who who were originally doing chemistry they worked in Latin the original language of science was was Latin especially when you're naming things so Fe just as a singular example comes from the Latin ferrous right so that's where it comes from now if you look in your periodic table you're going to notice a good handful that don't match the first letter here and that's because it's some Latin root you could probably look it up somewhere if you were curious but you're just going to have to get used to Fe being iron sodium is another example sodium you might have heard of sodium it's an essential thing that your body needs sodium is in table salt sodium chloride but sodium is not s o or s sodium is actually na in chlorine just as an example CL now this one obeys or sort of abase CH l CL is how we abbreviate for chlorine so there's tons of elements tons of different atoms in the periodic table I just put a handful here just to kind of break down the barriers a little bit and help you realize that these mysterious things that we call elements these mysterious things that we call atoms they are things that are all around you you definitely touched carbon you definitely breathe the oxygen you definitely you know touched and handled all of these things in your life before maybe in microscopic amount so you really didn't know about it so the concept of an atom if you take anything apart far enough if you take that water and you break it apart and you get that hydrogen and you get that oxygen those are going to be the fundamental building blocks of what we call the elements now I am going to go and give you a little bit of a segue here because I'm a physics guy at heart you know that sort of first love was always chemistry but I ended up pursuing physics a little bit later in life but I'm going to go and tell you now that now we know with modern science that you can actually take an ant atom here and break that atom up into what we're going to talk about a little bit later the protons the neutrons and the electrons that form that atom and we'll get into that a little bit later so don't worry about it we're going to talk about those things and furthermore you can actually take a proton or or a neutron and you can split them up even more into these these even tinier subatomic particles that's why they call them sub atomic subatomic because they're smaller than the atomic particles in the nucleus there and you can split them up even more so really there's no end to how much you can split these things up but when we say in the chemistry books that an atom is the smallest elemental unit of a sample of matter what we mean is that if you break them up that's the smallest unit where everything sort of retains some identity in other words if you get down to a chlorine atom it's going to have some properties chlorine will kill you pure chlorine if you breathe it will kill you just like that right sodium is extremely reactive if you take sodium and you put it in a bucket of water it will spontaneously burst into flames no match no nothing it'll just start igniting right so these are different properties because these are different atoms but if you bust these atoms apart into the protons and the neutrons then you sort of lose the identity of what the thing was because all the protons really look the same all the neutrons really look the same inside of an atom all the electrons really look the same so when we say the atoms the smallest Elemental unit we're not saying you can't break an atom apart anymore we're just saying that that's the smallest unit where things sort of have some identity different properties right different melting points different reactivity things like that all right so that's an atom now what happens if you take some of these atoms and put it together we already talked about that a little bit if we take carbon and put it with oxygen we might get carbon dioxide we might get carbon monoxide both of those gases will kill you if you breathe them too much anyway and our body produces carbon dioxide you already know that as well so let's talk a little bit about the molecule now keep in mind we are going to revisit these things especially the molecules and spend a good chunk of this course talking about how molecules are formed this is just an introductory thing what this is a molecule is a larger it's a larger unit in which two or more atoms are joined together and that's kind of I think what most people think about when they think about a molecule they think about this this chemically joined thing that has some properties like the water molecule that's probably the most common molecule everybody knows about we drink it every day it's oxygen and hydrogen put together and so I'm going to take this opportunity to write down something that I know you already know water is h2o and we are going to get into this a whole lot later but what this is basically saying I think most of you know is it's two atoms of this guy we call hydrogen which is an explosive gas very reactive combined with one atom a heavier atom which we call oxygen that we breathe and so these things come together heat is involved in that reaction and this guy is a molecular unit that means that if we go and take a microscope and look at this a sample of water we'll see if we could see molecules right because they're really small but if we could see them we would actually see little units floating around with two hydrogen's and you know one oxygen that's a molecular unit right and the properties of water have nothing to do with the properties of the things that make up the water it's a unique thing that sort of has its own properties its own melting point its own boiling point totally different from that of which it's made which is why we have such an incredible variety of everything out in the universe here you know another example of a molecule might be carbon dioxide co2 the dioxide means - diamonds - that's a prefix we'll learn a little bit later on when we really get into naming these things this is just some quick examples so we put carbon and oxygen together we get carbon dioxide we might also get instead of carbon dioxide we might get carbon monoxide which is one atom of carbon for every one atom of oxygen so you see these are the same elements join together but we have two different stable molecules here we have two oxygens along with the carbon we also have one oxygen along with the carbon so we have a whole potpourri of things that can be created here in fact some elements I'll give you a little preview of something we'll talk about later some elements can sort of form their own little molecules the ever heard of o2 oxygen in terms of oxygen you may hear in TV or something like we'll turn on the o2 or you know somebody's in the hospital they'll turn on the o2 - the patient that is oxygen gas so that's because the element oxygen the thing that we're calling oxygen here see I just put o here on the board but it turns out in real life oxygen along with a few other elements like nitrogen is another one they don't really exist just one atom by itself they really love to bond with themself I don't know why they just love each other in fact we do know why we'll talk about why later later on in the course but some of these atoms if left alone will just sort of pair up and bond and that's totally stable so when you get a bottle of oxygen you know at the hospital it's not pure single atoms of oxygen floating around in there they're all bonded together in these little molecules of o2 gas same thing with nitrogen you're always going to find nitrogen as in - right you're always going to find hydrogen as h2 okay not all gases do that but some of them do we'll talk about will give you a whole list of which ones do that a little bit later in the course but my point is is we're talking about the concept of the molecule so molecule could be these guys right here hydrogen two of these guys bonding with oxygen we could have carbon bonding one oxygen like like this two oxygen atoms we could have 1 & 1 or we can have the same atom bonded to itself these are all molecules so a molecule is just basically telling you that the atom can join in form these sort of larger units so that's what we're going to talk about we'll spend a good chunk of the whole course talking about molecules who come back to this later now we're going to talk about the concept of a chemical reaction a chemical reaction what is a chemical reaction I think most people have a really good idea of what a chemical reaction is but just to make sure what we're going to say here is that it it occurs when matter undergoes a change in composition and or a structure of its molecules all right so that's why the chemical reaction is basically you take two things two could be two elements you're putting together could be two molecules of more complicated bindings of elements that you put together and a rearrangement basically happens when you take the vinegar which is a chemical you know formula that well we can write down the board later and you take you with the baking soda which is another chemical formula that we can write down talk about later the details aren't important right now we can take and put them together spontaneously because of the way the chemistry is involved these guys really like to dance so when we put them together the electrons begin to be shared the elements begin to be joined in different ways and new products are formed which are different combinations of those elements that have come together and that's basically what a chemical reaction is the oxygen in the air combines on the atomic level with some of the iron that's sitting in your front yard and it produced iron oxide that's rust the properties of iron oxide are really not not like iron iron is a nice shiny metal iron oxides Brown rusty brittle looking powdery looking substance and of course the oxygen in the air is a gas so iron oxide isn't like anything like that properties are totally different but basically a chemical reaction is a when matter undergoes a change of a structure of its molecules and we'll talk about why later but basically what happens is electrons begin to jump around elements become reattached to maybe the other guy that you're mixing it with and out spits new products okay I'll say one more thing here I've already hinted to it but you know you may have something on your test you may have something in your book I just want to make sure there's no confusion when we talked about the concept of a of an element really for the the way I'm teaching in here it's the same as an atom you know all the periodic table of the elements that's what we call it the periodic table of the elements they're all just different atoms with different number of protons and neutrons and electrons we'll talk about all that stuff later so you know I could have kind of joined this with the definition of the atom but you know some some definition some some examples of some elements would be you know oxygen like we talked before nitrogen sodium which is na argon gas you know what about neon like a neon sign those are all different elements which are all just different atoms so basically element and atom for the purposes of a chemistry class they're basically synonyms so if you're if you're reading a sentence and you see somebody talk about atoms and you read another sentence and they're talking about element on the periodic table you can basically just equate those two in your head that's going to get you pretty far all right one more thing I'll talk about here before we move on to topic to a different topic and that is compound you know it can confuse people at first what's the difference between a compound and a molecule because most of the time I'll tell you right now most of the time mentally you can equate those two things a compound and a molecule more or less you can think of them as the same thing because they really are the same thing one is a subclass of the other really let's talk about what that is a compound is a molecule it's a type of molecule in other words where put it like this it's a molecule made up of two different elements so honestly it's really just a definition more than and once you learn this you probably never have to use this again but let's talk about a couple of examples co2 carbon dioxide two different elements make this guy up carbon element carbon and the element oxygen right so because two different guys make this up it is a compound and of course it's a molecule in other words everything I list here is going to be molecules because a molecule a molecule is the general term molecule is just sort of like any you know when two things combined together we say it's a molecule right we say it's a compound when the two things that come together are different elements so let's give a couple more examples and I think you'll understand what about water you know we talked about the water molecule so of course it is a molecule but it's also a compound because it's two different elements that form this guy so you may ask yourself well if these guys are compounds and molecules what could come together that you know would not be a compound well the answer to that would be oxygen gas let's say I already told you that oxygen when you get it in a tank it's not just single oxygen atoms floating around they're bonded together always Oh - that's why you hear it so much you know maybe in the movies or whatever so this guy is not a compound but it is a molecule is a molecule so in other words like I said all these things are going to be molecules because the molecules in general when any two things comes together these guys are not different they're the same exact element so if we don't say it's a compound another example would be hydrogen gas or nitrogen gas anything that comes together that's the same element it's not going to be a compound but it is going to be a molecule so because of that there aren't too many things that we talk about that are going to bond together with itself you know these gases are some examples they're probably some other examples out there most of the time you can use compound and molecule totally interchangeably because most of the time the elements that make up your molecule are going to be different elements 99.9 percent of the time but this is just a definition thing so on your test if you're asked you know what's the difference between a compound and a molecule and you'll know the answer you'll know what the definition really is all right let's go ahead and wrap this section up by talking about mixtures what is a mixture I think most people have a pretty good idea what a mixture is mixture it is when two I'll call them substances are you guessed it mix together and I'm going to go out of my way to say that there's no chemical reaction here you know the reason I bring this up isn't because it's terribly relevant to the rest of the course mixtures really aren't that terribly relevant at least you know for now but the reason I'm bringing it up is because almost all chemistry books have this in the beginning we talked about mixtures and that's just so that you understand that not everything that you mix together is going to react in a chemical sense let's say you have a bucket of water you know and then you take some sand and pour it into that water or maybe some rocks or maybe some flour or something like that and you pour it in that water you mix it up and it's a real nice mixture but there's no reaction there in fact if you let that sand just sort of sit off in a corner by itself that sand is going to settle right back down to the bottom and the water is going to be right on top there's no chemical reaction there's no elements that's you know doing any kind of rearrangement on any kind of molecular or atomic level everything is just sort of there and it's in the same space but it's not actually chemically combining that's what we call a mixture all right so to give you a few more definitions we say that we have a homogeneous mixture okay homogeneous mixture and that's a mixture that has the same composition everywhere okay what would be a good example of a homogeneous mixture that would be an example would be salt dissolved in water h2o where in chemistry class almost our writing water is h2o salt dissolved in water so the salt is not really chemically combining with the water in other words we're not forming a new compound with hydrogen and and sodium you know we're not actually rearranging the the atoms there to produce something new but what does happen is the the salt atoms sort of that kind of fit between all of the water molecules so that salt that you pour in there it kind of disappears well it doesn't really disappear it's just that the salt crystals break down so small that the little atoms of sodium chloride the salt kind of fit between the modern molecules so we say it's dissolved now if you take a sip of that water from the top it'll taste pretty salty right now if you take a straw and put it to the bottom assuming you've mixed it well then you take a sip from the bottom it's going to taste pretty salty more or less it's going to be the same saltiness as the top of the water for you know from the bottom of the water so the mixture so to speak has totally evenly distributed everything everywhere so it's the same consistency at every single point totally unlike the sand that we talked about a minute ago that's not mixed well at all it's totally separated but the salt example everything's mixed together well so we call it a homogeneous mixture the prefix homo means the same so when you think of that think of it that way homo means the same so it's the same composition everywhere so since we're talking about different kinds of mixtures we have a homo genius mixture then you would also have a heterogeneous mixture all right and so from this example you probably should be able to figure out hetero means different so what this means is that the mixture varies in composition from place to place okay and the example that we just talked about is sand and water yeah you can mix it up really well and it will look pretty good but after five minutes that sand is going to settle to the bottom so that's heterogeneous rocks in dirt you don't have to have a liquid to have a mixture I mean you can have potting soil dirt and you can mix some rocks in there but unless you mix it you know incredibly well the odds of the composition of that mixture being exactly the same everywhere pretty low especially if you just pour some rocks in there and give it a little bit of a stir you're going to have some clumps of rocks over here some clumps of rocks over here it's not going to be totally evenly distributed so we call it a heterogeneous mixture well that about does it this is a good introduction to chemistry I hope I've given you a little bit of motivation chemistry is something that you see every day it's all around you every time you breathe in a breath of oxygen that oxygen goes into your cells there are chemical reactions taking place that basically turn that oxygen and they basically burn the fuel that we that we eat and drink every day make energy which allow us to move and walk around you know we may build a campfire that's a chemical reaction there that's liberating energy from that wood from the chemical reaction that goes on between the wood and the oxygen so what we're going to do in the remainder of the course we're going to cover some foundational material first and then we're going to talk a whole lot about the periodic table and all I won't say all the elements but we're going to go through most important elements that you'll use in your in your chemistry class regularly talk about the structure how the periodic table is put together we'll talk then about how these elements come together to make these molecules and then we've kind of given you some examples but we want to be able to predict we want to be able to know what's going to form if we mix these two elements together right and will they form anything at all some things won't form anything if you mix them together how is that the case so we're going to talk about that after we do that then we'll expand our scope a little bit more and we'll talk about taking molecule a which let's say it's water and then molecule B could be some some other molecule that we have you know sodium chloride you know potassium hydroxide whatever and we mix them together will they react will they form a new product over there and if so how much product will form if we have X number of grams of things that we're mixing together we call those the reactants the thing that we mix together we call them the reactants how much product are we going to produce in terms of grams so that's where we're going we're going to go talk about elements compounds we're going to talk about mixing these compounds together to make a chemical reaction balancing the chemical reaction and computing what comes out on the other side I'm Jason I hope I've given a good introductory lesson to chemistry stick with me we're going to go through every single topic step by step with lots of examples to make sure that your chemistry class is enjoyable and that you know how to do well in your lectures on your quizzes and on your exams

Channel: Math and Science

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Rating: 4.9096513 out of 5

Keywords: chemistry, intro to chemistry, introduction to chemistry, chemistry basics, online chemistry course, online chemistry, chemistry course, chemistry class, chemistry problems, chemistry practice, chemistry 101, chemistry homework help, chemical reaction, chemical compounds, chemistry compound, chemistry element, chemistry 1, college chemistry, university chemistry, high school chemistry, learn chemistry, learn chemistry for beginners, learn chemistry fast

Id: k3rRrl9J2F4

Length: 38min 14sec (2294 seconds)

Published: Thu Feb 04 2016