Transcript for:
The Periodic Table and its Organization

in this video we want to look at the periodic table and how it's organized so here we see a periodic table so what we're going to talk about are the different types of elements that we'll be seeing on the periodic table how are things arranged horizontally and vertically on the periodic table as well as why the periodic table doesn't have that perfect square or rectangle shape when you're looking at this you're going to see that it's not a perfect square or a rectangle it kind of has this odd and peculiar shape to it these are some of the things we're going to talk about in this presentation the first thing we want to look at is grouping elements on the periodic table into three main categories and you see these three main categories on this periodic table the metals the metalloids and the non-metals we want to notice is that the metals are the biggest part of the periodic table these are the ones that are shaded in blue on this periodic table they're kind of in the middle and on the left hand part of the periodic table your non-metals those are those shown that in green on this periodic table those are the ones that are in the upper right hand part of the periodic table and then between the metals and the non-metals in the orange color are the metalloids so we want to go through and talk about each one of these groups of elements so the periodic table can be organized by what type of element you are looking at and the first one we want to look at are the metals because these are probably the ones that are most common to us these are ones that you're probably most familiar with our metals are located on the middle and the left hand part of the periodic table and when we think about metals usually when we're thinking about metals metals are often solids at room temperature we're kind of familiar with that metals also generally are shiny in appearance especially when there's no coding on them or they haven't reacted with anything they tend to be very shiny in appearance think about a brand new penny a new coin a gold ring they tend to be very very shiny in appearance metals tend to be very workable now what does that mean that means it's pretty easy to shape metals into the specific sizes shapes dimensions that we want in order to build things out of they tend to be both very malleable so malleability means that they can be pounded into very very thin sheets they also tend to be very ductile ductile means they can be pulled into thin long wires metals tend to be very good conductors of both heat and electricity you're familiar with them being good conductors of electricity they're used for wires in all sorts of electronic devices they're also good conductors of heat you're familiar with this as well think about your seat belt buckle on a hot summer day when you just get into your car they heat up very very quickly metals that's why that seat belt buckle is so hot when you get in it on a warm sunny summer day they also will cool down very quickly as well those are all the physical properties that you would associate with metals there's also some chemical properties we want to talk about and the main chemical property we want to deal with is how they deal with electrons previously we've talked about electrons being the currency in chemistry those are the action items in chemistry are those electrons so how will metals deal with electrons well metals will tend to lose electrons now if we remember electrons are negatively charged so when you remove a negative charge the end result if you get rid of a negative you're going to be positive so these will form positive ions if we compare metals with nonmetals this is a very useful kind of term we may not be from as familiar with nonmetals but just in what we name that category non-metals that literally means not metals so we're expecting some of the exact opposite properties that we saw with the metals for our non-metals for our non-metals we're looking at these being on the upper right hand side on the periodic table our nonmetals will have both solids liquids and gases at room temperature pretty good representation of the different states of matter remember that our metals tended to be shiny in appearance our non-metals will be very dull in appearance they also tend to not be very workable materials it's very tough to work with them in terms of manufacturing them into specific dimensions sizes shapes now a lot of them are gases that's very tough to make gases workable into specific sizes and shapes but even the solids tend not to have the same structural integrity that you find with metals the solids in our non-metals tend to be kind of powdery or brittle solids that make it tough for them to be worked into the exact sizes and shapes that we might desire non-metals are also poor conductors of heat and electricity they don't conduct electricity very well they don't conduct heat very well either so a lot of the exact opposite physical properties for the non-metals compared to what you saw for the metals our non-metals will also have the opposite chemical properties as well metals tended to lose electrons to form positive ions our non-metals will gain electrons to form these negative ions we kind of look at that what forms in between metals and non-metals on the periodic table those are the metalloids these are located between the metals and the nonmetals on the periodic table they have some of the same properties of metals and non-metals they're kind of that in between they are semiconductors they don't conduct really well but they don't not conduct either some of them can be shiny some of them are dull they are kind of in that in between land some of them will form positive ions others negative ions they're kind of that in between land between the extremes of metals and non-metals okay i'm looking at the periodic table again not only will those metalloids be between the metals and the non-metals in terms of their physical and chemical properties but also due to their location on the periodic table you see they're kind of located between the metals and the non-metals that was one type of organization organizing by metals non-metals and metalloids there's another type of organization we can go through the periodic tables also organized by periods and groups we'll start with the periods our periods are the horizontal roads that you're seeing on the periodic table and if we just kind of go down period one period two period three four five six and so on these are the horizontal rows we don't call them rows we call them periods we won't spend much time on the periods what we'll spend more time on are the groups the groups are the vertical columns that you see on the periodic table except we don't use the term columns we use the term group sometimes you may also see the older term families for this and there's two different ways of numbering the groups on the periodic table one way that you see is just going right across one two i'm highlighting these in yellow three four five six seven eight nine 10 11 12 13 14 15 16 17 18 across this is the more newer modern way of organizing the groups on the periodic table but here's a case that even though it's a little bit more new and modern no one actually ends up using that way everyone still uses the older technique with the a's and the beads that i'm going to highlight in green 1a 2a across the middle are all these different b's then when you get back to the right hand side of the periodic table we get 3a 4a 5a 6a 7a and 8a we're going to use the older group numbering because what we'll see in future units is if you use the older group numbering you get access to some useful important information right away by doing that we want to talk a little bit more about the groups than we did the periods because it's the groups that end up giving us this kind of unusual shape on the periodic table periodic table is really organized by the groups elements that are in the same group will have similar chemical properties so if we look on that first group group 1a hydrogen lithium sodium potassium rubidium we're looking at all these elements in this first group that i'm highlighting in yellow that means that there's some similarities between those they have similar chemical properties they belong to the same group the same family so that's why the periodic table is not a perfect square not a perfect rectangle because we're organizing things such that if they're in that same group there's going to be some common chemical features between them so just some things we talked about while looking at the periodic table the periods are the horizontal rows on the periodic table the groups are the vertical columns on the periodic table we saw the two different numbering systems for the groups the older system that uses the a's and b's sometimes instead of numbers they'll often use roman numerals as well and the newer system that just goes one through eighteen as we talked about already we're going to be using the older system as that provides direct useful information that we'll see later in the course elements in that same group have similar chemical properties again and it's that's reason why the periodic table isn't a perfect square or a perfect rectangle because of the organization by groups now some of those groups besides being numbered specifically have common names that we want to be familiar with so i just want to quickly kind of go through these common names and properties for right now we're going to just focus on the names i'm going to mention the properties and the properties are going to be what ions get formed these aren't going to be needed right now the ions of what get formed but you'll see in a little bit in a couple chapters we're going to be using that information of what ions get formed so let's start with group 1a group 1a does have a common name those are the alkali metals so we need to be familiar with that name because that name comes up and is commonly used to describe that group and the chemical feature that we'll see in future units that we're going to use is these will form plus one ions group 2a does have a common name that we need to be familiar with these are the alkaline earth metals and that common feature that we're going to use in the future is that these are going to want to form plus two ions now all of the beans these are the things you're seeing in the middle of the periodic table we kind of group all of them together and call them the transition metals so these often get grouped together they're metal so they'll form positive ions but what we'll see with these transition metals is they'll form positive ions but of a lot of different charges you can't kind of pin them down to one specific charge so we keep on going once we get through all the transition metals in the middle of the periodic table we re pick up the a's group 3a all these groups technically have names but if they're not commonly used there's no point in memorizing them no commonly used name so we don't have to worry about that but their common chemical feature usually will form plus three ions group four a again no commonly used name but these will usually not form any ions occasionally they will but for the most part you want to associate this group with no ions form group 5 a next group over again no commonly used name these will usually end up forming negative three ions notice that we're starting to get over to the right hand side of the periodic table we're kind of through with the metals we're starting to pick up the nonmetals so now we're seeing negatively charged ions being formed here group 6a again no commonly used name but usually you're going to see negative two ions coming from that group when we get over to group 7a group 7a does have a commonly used name that we want to make sure we're familiar with these are the halogens and that common chemical feature of the halogens is they will usually form negative one ions the last group all the way on the right group eight a does have a commonly used name that we need to be familiar with those are the noble gases and their common chemical feature is no ions that term noble gases kind of hints at that of noble is kind of used in that old english style of you know noble inert unreactive these aren't going to form any ions again for right now what we need to be concerned with are just the group numbers and the names that are used for them things like the ions that are formed whether it's plus one plus two plus three we won't use them right away but in the future we'll be using that information a lot so here you just see the periodic table again in terms of everything we just talked about so when we look at two elements if i look at group 2a and i look at magnesium and calcium the fact that they're in the same group those alkaline earth metals that's telling me that they're going to have similar chemical properties and the chemical property that we talked about that we'll be using in the future is plus two ions but for right now we're just going to focus on the organization the group numbering and the specific names that are used to describe those most common groups