in this video we're going to talk about the periodic table of the elements now there's two important things you need to know about this the columns are called groups the rows are called periods so this is group 1 group 2 3 4 5 6 7 8 9 10 11 12. and so forth now the elements in a group share similar chemical properties for instance group one is known as the alkali metals the alkali metals include lithium sodium potassium rubidium cesium and francium hydrogen is not considered to be an alkali metal the alkali metals they're very reactive all of these metals they react violently with water some of them blow up with water in fact their reactivity increases as you go down a group which means that cesium is much more reactive than sodium in fact if you put cesium in water it can blow up there's a lot of youtube videos that demonstrate this reaction whereas if you put sodium in water it'll react vigorously but it may not blow up as quickly as cesium would one of the reasons for this is that cesium has a much lower melting point than sodium in fact the melting point of the alkali metals decreases as you go down the group alkali metals have a much lower melting point compared to other metals the melting point of cesium is around 29 degrees celsius whereas the melting point of iron is around 1500 degrees celsius so we need to understand is that elements in a given column they share similar chemical properties compared to elements that are not in the same column so for instance group 16 these elements are known as the calcagens they share chemical similar chemical properties these elements here group 17 are known as the halogens they're non-metals and they have a similar chemical reactivity so elements in the same group share similar chemical properties the alkali metals also have low density values the density of lithium and sodium is less than water in fact those elements will float on water whereas if you were to put iron metal in water it will sink to the bottom because iron metal is much more dense than water now the next column group two this group is known as the alkaline earth metals they include beryllium magnesium calcium strontium barium and radium the alkaline earth metals are reactive but they're not as reactive as the alkali metals the alkali metals are much more reactive than the alkaline earth metals next we have the transition metals the transition metals have multiple oxidation states now just to compare and contrast when the alkali metals when they give up their electrons they form ions with a positive one charge so think of sodium plus or potassium plus when the alkaline earth metals give up their electrons they form cations with a two plus charge so think of magnesium two plus calcium two plus strontium two plus now the transition metals they can form ions with variable charges iron for instance it can form the two plus ion or the three plus ion copper there's copper plus one there's copper two plus so the oxidation states the charges that the transition metals can have can vary widely now let's move on to the next group so we discussed the calculus and we also talked about the halogens the halogens include fluorine chlorine bromine and iodine the calcagens include oxygen sulfur selenium tellurium and polonium next we have the noble gases the noble gases they're chemically inert they're not reactive for the most part they don't participate in chemical reactions it's extremely hard to get them to react with other elements so we have elements like helium neon argon krypton xenon and radon those are the noble gases they're chemically inner now there are other ways of naming the groups so group one is also called group 1a group 2 is group 2a group 13 that's group 3a 14 is 4a this is 5a 6a 7a and 8a now those values also correspond to the number of valence electrons found in the elements of that group so let's talk about that next so group 1 or group 1a this group has one valence electron group 2 has 2 valence electrons group 3a has 3 valence electrons group 4a 4 valence electrons and then five six seven eight helium is an exception to this helium has two valence electrons but the elements below that the other noble gases like neon argon krypton they have eight valence electrons a valence electron is the electrons that are in the outermost energy level or the last energy level of an atom now the number of electrons gives us an idea of the type of charges that these elements will form but before we talk about that let's talk about metals non-metals and metalloids on the left side of the periodic table we have the metals metals are electrical conductors they allow electricity to flow through them they can also conduct heat they're malleable they can be hammered into sheets they're ductile they can be pulled into wires copper and silver they're commonly used to form wires in electrical circuits metals they also like to give away electrons and as they do so they become positively charged ions known as cations on the right side of the periodic table we have nonmetals the halogens are considered to be non-metals but the other non-metals which i highlighted in blue that is in this group these nonmetals they like to take electrons metals like to give away electrons and non-metals like to take electrons whenever a nonmetal takes an electron it becomes negatively charged negatively charged ions are known as anions positively charged ions are known as cations metals like to form cations non-metals like to form anions so the elements in group one the alkali metals they like to form positively charged cations with a plus one charge because they only have one valence electron to give away the alkaline earth metals they have two valence electrons when they give up those two valence electrons they will form a cation with a positive two charge so thus we have ions like mg2 plus aluminum which is in group 3a or group 13 it's going to form an ion a positively charged ion with a three plus charge so as you can see metals form cations ions with a positive charge and the charge is based on the number of electrons that they can give away non-metals like to form anions ions with negative charges fluorine is a halogen that has 7 valence electrons it's in group 7a or group 17. now the nonmetals they like to take electrons so that they can have a complete octet they want to have eight valence electrons fluorine has seven it needs to acquire one electron to have eight so fluorine will form an ion with a negatively one or negative one charge the calcagens have six valence electrons they're part of group six a and they need two more to get to eight so they like to form ions with a negative two charge so we have oxide which is o2 minus nitrogen and phosphorus they have five valence electrons they're both nonmetals and so they like to acquire electrons so they need three more to get to eight so when they acquire the three electrons that they desire they will have a three minus charge or negative three charge so that's how you could determine the type of ions that these elements will form metals like to give away electrons to form positively charged ions and non-metals like to take electrons to form negatively charged anions now keep this in mind the noble gases are non-metals they are not metallic but even though they're not metals they don't behave the same way as the other nonmetals these nonmetals here between groups 4a and group 7a those nonmetals they like to acquire electrons the noble gases they're nonmetals but they don't like to acquire electrons nor do they want to give away their electrons they are already complete they're happy they're satisfied they don't want to do anything they just want to chill so make it make sure you understand the distinction between those two types of nonmetals the nonmetals they don't conduct electricity unlike metals metals are malleable and ductile but the nonmetals they're brittle between the metals and the nonmetals we have a group called the metalloids the metalloids they don't conduct electricity as well as metals do but they're not insulators like the non-metals they can conduct a small amount of electricity so they're called semiconductors two common semiconductors that you'll encounter are silicon and germanium the electrical conductivity of semiconductors increases with temperature so if you were to heat up silicon or shine light upon it it's going to conduct electricity better compared to if you didn't do those things so metals they actually become less conductive if you increase the temperature in fact if you can cool a metal down to absolute zero it can behave as a superconductor metalloids or semiconductors they behave differently their conductivity increases with increase in temperature now we talked about the vertical columns being called groups one thing i didn't mention yet are the rows the rows are called periods so this is period one period two period three and so forth over here you have the lanthanides and the actinides the lanthanides they should be after barium so starting with element 57 you have the lanthanides after 88 you have the actinides which starts at 89. so those are some other terms you need to be familiar with the lanthanides and ancinites now the next thing we need to talk about is the stuff that's found next to the element so the letter represents the symbol of the element h stands for hydrogen the top number is the atomic number the atomic number is the same as the number of protons the atomic number identifies the element so hydrogen always has one proton helium always have two protons in its nucleus beryllium will always have four protons in its nucleus the number on the bottom which is usually not a whole number it's a decimal value it represents the atomic weight but more specifically the average atomic mass of that element in its natural state on earth now for instance if you look at carbon you'll see that the average atomic mass is 12.01 the reason why it's not exactly 12 is because there are different forms of elemental carbon known as isotopes there's carbon 12 which can be written that way when it's written that way the six is the atomic number the top number is the mass number there's other isotopes of carbon there's carbon 13 and is also carbon 14. the mass number is the sum of the number of protons and neutrons so carbon-12 has six protons six neutrons carbon 13 has six protons seven neutrons carbon 14 has six protons eight neutrons but all forms of carbon have six protons which is the atomic number which identifies the element now notice that the average is close to 12. 12.01 what that tells you is that this particular form of carbon is the most abundant isotope of carbon on earth carbon 13 and carbon 14 they're pretty rare so more than 99 of all the carbon atoms on earth will be in the form of carbon 12. less than one percent is carbon 13 and carbon 14. so if you have let's say a hundred atoms of carbon probably one of them will be carbon 13 and most likely the other 99 will be carbon 12. now since you're watching this video it's likely that you're going to be quiz on the names of the elements so for instance if you're given the chemical symbol of the element li you need to know that this refers to lithium if you see the symbol be on your quiz you need to know that this is beryllium so let's talk about the common elements that you're most likely to be quizzed on first we have h hydrogen hydrogen is the fuel that powers the stars of the universe the sun converts hydrogen into helium in a process known as nuclear fusion helium he it's found in hot air balloons well not hot air balloons but balloons that tend to rise if you put helium in a balloon because helium is less than air those are the balloons that will go up they won't fall to the ground but they'll float high into the sky unless you hold them lithium is found in lithium-ion batteries sodium is found in table salt table salt is sodium chloride it contains sodium and chlorine in its ionic form magnesium is found in water calcium is found in your bones potassium in its ionic form k plus is found in bananas bananas are high in potassium know this one iron metal fv doesn't sound like iron but fe is known as ferrous or ferric which is associated with iron when you see see you think of cuprus or kubrick that's associated with copper c-o is cobalt and i is nickel the nickel five sense actually contains copper and zinc but think of nickel cadmium batteries that's where you'll find nickel cd is cadmium copper is found in wires the same thing as silver gold is the storage for wealth pt is platinum ir is iridium those are also rare metals pd palladium aluminum think of aluminum foil and gallium that's a metal that can actually melt in your hand mercury is already a liquid at room temperature so think of liquid metal that's mercury carbon there's many forms of carbon perhaps you heard of carbon dioxide that's the stuff that we breathe out perhaps you heard of graphite in inside your pencil graphite can actually conduct electricity it's an elemental form of carbon diamond is another form of carbon diamond is pure carbon the same as graphite is fear carbon but diamond doesn't conduct electricity it does conduct heat graphite can conduct electricity so graphite and diamond they're allotropes of carbon they're both pure elemental forms of carbon but they have different structures silicon is found in solar cells germanium can also be used to make solar cells as well when you see ascendus represents tin think of a tin can pb is lead think of lead acid batteries found inside your car nitrogen is found in the air almost 80 percent of air is composed of nitrogen or 79 actually about 20 of air is composed of oxygen then we have phosphorus sulfur selenium te telerum now you need to be familiar with the diatomic elements nitrogen is diatomic it's a molecule composed of two atoms of nitrogen oxygen gas is diatomic oxygen has two forms oxygen gas the air that we breathe in and ozone o3 which is found in the upper atmosphere so these are allotropes or two different forms of the element oxygen next we have fluorine fluorine is found in toothpaste in the form fluoride next chlorine that's also diatomic chlorine is typically used to disinfect pools and then you have bromine and then iodine iodine is found in table salt in the form iodide next we have neon think of neon lights there's argon argon is found in the air krypton i think of superman's kryptonite and then we have xenon and then radon now radon's interesting because radon can be formed from the decomposition of uranium thorium or radium and because it's a gas it can actually come from the ground and go up into your house so if your home doesn't have good ventilation if you don't open the windows over time radon can build and this is a radioactive gas that can be hazardous to your health so it's good to open the windows of your house to prevent the buildup of radon in your home these elements which i kind of touched on some of them these elements are very rare and they're expensive silver gold palladium platinum the price of these metals are very high we talked about uranium a little uranium is radioactive that's found in uh it's used for nuclear fission it's used in different nuclear reactors as well and there's other elements to talk about but we've covered the common ones so that's basically it for this video so make sure you know the names of the elements and the symbols that correspond to them and that's that thanks for watching