are you ready to start talking about the periodic table you need to get your periodic table out if you don't have it already out because you're going to want to write on it so the periodic table the main idea behind the periodic table was that elements in a given vertical column have similar similar chemical and physical properties and there was a lot of development that went into the table a lot of prediction that went in different forms of it that were developed before we came to our current day period table when you look at the table itself you'll see normally something looks like this you may or may not have the name down here a lot of pair of tables we don't put the name on because we know the name based on the symbol but what you should should know is that above you will always find your atomic number so the whole number listed above is your atomic number the periodic table is listed in order of increasing atomic number so it goes one two three four five six just chronological order all the way up in order of increasing atomic number remember this atomic number is the same as the number of protons of that element we also have your elemental symbol remember elemental symbols capitalized first letter lowercase second letter and be careful with these some of them seem intuitive but some of them are not as intuitive so you've really got to pay attention to making sure you have the right element listed and again you may or may not find the name there but you will find this value here and this is your atomic weight and that is that value that's found from that weighted average we were discussing so again main idea of the periodic table is that it's been constructed so that elements in a given vertical column have similar chemical and physical properties if you read across the table the table increases an atomic number chronologically and we also see it increase the mass as we go across the table the table though gives us a lot more information that we we use it as a tool it's a great tool we don't have to think about it we can just use it if we know how to use the table properly there's a lot of information we can delve off of it without having to memorize it so mendelev um there's a lot again a lot of work went into developing this table but mendeleev is one of the forefathers of the table and he organized the elements into a logical pattern but left spaces for these undiscovered elements based on predicted properties he did incorrectly arrange them in order of increasing atomic mass now if you look at a table you may say but it is increasing by atomic mass yeah kind of but it's really increasing by atomic number it's really increasing by the number of protons the atomic mass just kind of factors into that you'll see a little bit of overlap between them for the most part it increases but it's not the heart of the table the heart of the table is really this increased by atomic number but the fact that by the time of mendelev so 1872 he was able to organize this in a logical pattern just blows my mind that you know 140 years ago or whatever 50 i can't even do the math that fast in my head um 150 years ago he knew they knew enough about these elements to already say okay we see similarities in these the properties of these different elements we're finding let's go ahead and put this in some kind of organizational system so that we have a better you know we can actually use this to our benefit and so not only be able to do that but to be able to leave spaces for undiscovered elements to realize hey there's some something missing here and to leave a space for it and also realizing that this would help us predict the properties of other elements so here's our product table which is kind of a cool picture showing you relative time of discovery so the light blue color was discovered all these elements were discovered before 1800 some have been around for you know more years than we can comprehend between 1800 and 1849 is where the darker blue elements were discovered 1850 to 1899 purple from 1900 to 1949 we get this darker brown color and now from 1950 up to through 2012 is when the ones in this yellowish orange color were discovered at this point more and more elements are being created it's nuclear chemistry it's physicists um they can create it by adding more protons to a nucleus of an element and it exists for short periods of time but after a certain point they really um after radium they are all radioactive at that point so stability in that they don't stay stable as long but again you'll get into that in the um second semester when you guys talk about nuclear chemistry kind of cool to me to see like how long have these elements really been not around we've most have been around like we knew that but when were they discovered and a lot of the elements are pulled out of different materials different ore um pulled out of the ground etc and extracted from different things and then we find that it's actually a new element which and that's how a lot of these were discovered you know before like the 1950s and i just think that's phenomenal i think it's such a cool concept so let's delve into the table itself what do you actually need from this well you need to be able to locate things like your main group elements your transition metals your inner transition metals you need to know the names and properties of these groups your alkali metals your alkaline earth metals your halogens and your noble gases you need to be able to locate the stair step line that separates your metals from their nonmetals you need to be able to identify common properties of metals non-metals and semi-metals alkaline metals first this is group one we will talk about the different groups on the table alkaline earth or group 2 halogens group 17 noble gases group 18 so let's first go ahead and look at where these things are located so i apologize in the slides a little bit busy but with this presentation program i have to do it by pdf which means i can't do transitions on it first we've got the numbers up here these numbers up here let me actually just highlight these these numbers up here are my group numbers so i see it goes through the number 18 1 through 18. this is um the new format for numbering the old format we'll also cover when we need that in a different chapter but groups one through eighteen group one metals are called alkali metals why is that important because they behave in a very specific fashion um if you've ever seen sodium dropped into water it it's kind of cool it's very reactive uh lithium not it's very reactive potassium even worse i mean the metals not sodium chloride sodium chloride is salt the metals themselves rubidium cesium look it up online can't do it um i can't do it safely in a lab it's just too exothermic it creates too much energy too much heat but group one metals are known as your alkali metals you need to be able to identify that all any element in this row so even down through cesium and francium i do not have all the elements listed here these are your alkali metals this is important because when we start getting into naming we're gonna find that all of our alkali metals in group one like to form plus one ions plus one cations they like a positive one charge group two here are alkaline earth metals so beryllium magnesium calcium strontium barium is under here again i'm not going to fill in all the elements on here it's just too much but you need to recognize that group two elements are called alkaline earth metals let's go over to group 16 um oxygen's family this is called the chalcogens i don't care if you know that name i actually didn't know the name so i started teaching it but you are responsible to know halogens and noble gases as well um so let me highlight so you do need to know alkaline metal alkali alkaline earth halogens noble gases halogens are your group 17 fluorine chlorine bromine iodine you need to know that those are your halogens they behave in very specific ways and noble gases they're called noble gases because they don't want to do anything once we reach like krypton xenon they'll start reacting with things just because they're so large they don't care anymore but they don't want to do anything there's a very specific reason why they're called noble gases and it's because they're non-reactive they've got everything they want and no reason to participate in any chemistry they are group 18 they are your noble gases we've got your transition metals transition metals are groups 3 through 12. so all elements within here are your transition metals all of this is transition metals transition metals have a variable oxidation state meaning they can have a different values for the charge on the atoms themselves are on the ions themselves when they form an ion they can form different charged ions iron can form plus two or plus three copper can form plus one or plus two there's a reason for it and we'll talk about how to be able to predict that when we get to that section in a different chapter but you do need to recognize that these are your transition metals this entire section is transition metals just as this entire section is alkaline earth metals and this entire section is alkali metals okay so all of your halogens all of your noble gases let's see erase that out of the way okay what else do you need to know um you need to know metals and non-metals so all of your metals are anything to the left of this stair step these are all metals anything to the right of this specific stair step are non-metals very few non-metals on the entire table but they make up a lot of our chemistry the stair step boron silicon going down this stair step here you need to recognize you need to identify the stair step so go from boron down to silicon and then it's boron silicon and then two two two angled down here these are called your semi-metals or metalloids these are what make up semiconductors they behave like metals but also like non-metals you need to recognize that stair step um your lanthanides and actinides are part of your inner transition metals so all lanthanides and axonites are inner transition metals but your lanthanides make up the first row and your actinides make up the second row but again all of them together make up your inner transition metals they're pulled out of the table because they just don't fit well space-wise in the table they actually are supposed to fit in up here um if you actually you can look online see how the tables actually constructed we pulled them out for space reasons but they behave in a similar fashion so you can show your lactone lanthanides and actinides and know that they're called inner transition metals you need to know your main group elements i recommend writing all of this all over your table and then studying it main group elements comprise groups one and 2 and groups 13 through 18. so not your transition models not your inner transition metals and you need to understand what groups and periods mean a group is a vertical column or family they used to be called families so you may have learned them as families depending on who taught you chemistry they're now called group but any vertical column so like your alkali metals are a group a period is a horizontal row so any horizontal row here is known as a period we do have an old numbering system and a new numbering system the new numbering system is 1 through 18 this is an the iupac numbering system all capital letters stands for international union of pure and applied chemists and they decided 1 through 18 was easier and i'm not going to disagree with that it doesn't make it it is a little easier to remember 1 through 18. the advantage of the old numbering system is it could help us identify some things later this um later in the semester so originally um group 1 was known as roman numeral 1 a roman numeral two a three a four a five a six eight seven eight eight a so through eight a and then your transition metals were b's so this was known as 1b through 10 b so if you see old numbering systems that's why you see roman numerals it's your older numbering system here's just another way to look at it your alkali metals your alkaline earth metals your noble gases halogens lanthanides actinides inner transition your stair step is shown in here separating out your metals and non-metals and remember on that stair stuff is where you get your semiconductors or metalloids um also known as semi metals because they behave sort of like a metal some of the time like a metal sometimes like a non-metal and then your transition metals so i had just had a couple different pictures so i know different people see them different ways so whether it be writing them out color wise whatever works best for you please use right on your own periodic table until you are comfortable understanding these things so you do need to be able to locate that stair step line separating your metals from nonmetals you need to identify the different groups we talked about we also need you to be able to identify common properties of metals common properties of nonmetals and be able to identify and define your semi-metals or your metalloids so metals what are some properties of metals well metals are known to be solid at room temperature the only metal that is not solid at room temperature is mercury actually there's only two elements on an entire table that are not either a solid or a gas at room temperature and it's mercury and bromine bromine just happens to be a non-metal so all metals are solids at room temperature except for mercury they have a reflective surface meaning they're shiny if you shine light on a metal it shines back at you metals are known to conduct heat they also conduct electricity if um if you're not from texas welcome if you are you know that when you go outside in summer and you accidentally touch the metal of your seat belts you really regret that decision because it definitely is conducting some heat right it heats up really really well they also conduct electricity they are malleable malleable means they can be shaped they can be formed into different shapes they're also ductile ductile meaning they can be drawn or pulled into wires metals lose electrons and form cations in reactions about 75 percent of the elements on that table are metals and they are we say lower left of the table lower isn't really the right word um but they are the left half of the table so when you're looking at the table and you've got that stair step and your lanthanides actinides all of it is your metals it's a huge portion of it our metals and so here's just a couple pictures of what some metals look like so we see copper and strontium most of us know what metals are but just kind of understanding they do have very specific properties because they're metals nonmetals nonmetals are actually found in all three states meaning solid liquid and gas at room temperature so we see here we've got sulfur as a solid bromine is a liquid and chlorine is a gas bromine is the only non-metal that exists exhibit or exists as a liquid at room temperature non-metals are poor conductors of heat they're also poor conductors of electricity they're used as insulators they're not going to conduct electricity they don't do anything they don't want to transfer that electron for you the solids are brittle if you have a non-metal cell they tend to be very brittle they gain electrons and form anions so whereas metals will always lose their electrons non-metals will always gain the electrons the reason being everyone wants to be like a noble gas they want a noble gas electron configuration we'll talk about electron configuration in chapter nine but if a metal can lose its electrons and get a noble gas configuration it lowers its energy metals it's easier for them to lose electrons than gain because they have to lose fewer than they have to gain to obtain that noble gas configuration non-metals are very close to the noble gases the noble gases are completely on the right-hand side of the table and so for a non-metal it makes a lot more sense for it to gain a few electrons than to lose all the electrons to be able to form that noble gas configuration and they are the upper right side of the table basically go to your stair step and they're over here on your periodic table except hydrogen hydrogen is listed above lithium on the table so you've got your block over here on the right hand side and hydrogen is listed up here it's listed here because of its electron configuration it is in fact a non-metal bow so oftentimes we push it over onto the other side of the table just to show the way it actually behaves and metalloids what is your metalloids your metalloids again are those compounds that fall right on that stair step silicon perfect metalloid um it's a semiconductor metalloids or semi metals exhibit properties of metals and non-metals so they're also known as semiconductors meaning they semi conduct heat they semi conduct electricity and there's huge advantages to using semiconductors sometimes we want to conduct sometimes we don't if it's in the same system sometimes it just makes sense to use a semiconductor so some properties included for metalloids let's look specifically at silicon it's shiny it conducts electricity it does not conduct heat well though and it is brittle so again go ahead and review the table you do need to be comfortable identifying where these things are on the table and understanding these terms and using them in your everyday chemistry language including understanding the properties of the different types of compounds we have in different elements