PERIODIC TABLE OF ELEMENTS | Science 8 Quarter 3: Module 4

[Music] the periodic table is this chart with a strange shape with letters and numbers neither a square nor a rectangle with such a characteristic shape unmistakable [Music] some people know what each of these letters represent C is the chemical symbol for carbon o is the chemical symbol for oxygen the chemical symbol for iron is Fe is zinc there are even those who know the chemical symbol for sodium is n a because it comes from the Latin natrium or that the chemical symbol for gold is a u because in Latin it was called Horus and also some know the meaning of the numbers that appear next to the letters like for example the atomic number which is the number of positive and negative charges of the atom but what exactly is the periodic table in 1869 a Russian scientist named Dimitri Mendeleev made a chart of the known elements the chart is called the periodic table of elements the periodic table is a chart that represents all 118 chemical elements that constitute the known universe everything around us is made up of at least one of these elements 94 of these elements can be found in nature and the rest were obtained in Laboratories 118 elements may seem too little for an entire universe but it's not let's see in stars like the sun 94 of all the atoms are hydrogen the human body itself is very scarce on chemical elements for every 100 kilos of weight 65 kilos are oxygen atoms 18 kilos of carbon atoms and 10 kilos are hydrogen atoms which leaves little room for all the other essential elements nitrogen calcium phosphorus potassium sulfur chlorine sodium magnesium iron Cobalt copper zinc iodine selenium fluorine The Wonder of the chemical elements is that they combine with each other and there's an almost infinite number of possible combinations that produce all the different chemical compounds needed to Keep Us Alive and build everything around us the water we drink obtained by combining an oxygen atom and two hydrogen atoms the glass we drink it from the sugar in our coffee [Music] Cup and the metal of the little spoon we stir it with [Music] the plastic our computer is made of the rubber on the tires of our car and the gasoline that makes it run proteins DNA everything around us and inside us are atoms that combined [Music] the distribution of the elements in the lines and Columns of the periodic table is not random or just a question of design the position of an element on the table tells us something about its chemical and material properties and helps us to know and predict how two elements can combine the periodic table shows elements arranged according to atomic number atomic number is the total number of protons in the nucleus each row across the table is called a period there are seven periods each element in the period has the same number of electron shells each column in the table is called a group or family of elements [Music] the two rows of Elements shown below the original table were discovered after Mendeleev developed his original organizational table this table shows you where they would fit in if we would add them to the original table we don't add them to the table because they would shift the original organization Mendeleev created putting the elements out of line therefore they are not highlighted when showing the groups all metals are on the left side of the table the metallic elements main group metals and transition metals have certain similarities including metals are malleable which means that they can be hammered into shape metals have a characteristic luster or shine metals are good conductors of heat and electricity metallic elements are solids at room temperature with the exception of Mercury metallic elements tend to lose electrons to form cations non-metals are on the right side of the table the properties of non-metallic elements vary more than those of metals the non-metallic elements are not good conductors of heat and electricity in contrast to the metallic elements the non-metallic elements can be solids liquids or gases at room temperature the non-metallic elements tend to gain electrons to form anions a step-like line separates them the third section the metalloid elements elements that lie just on either side of the line that separates metals from non-metals are known as metalloids the metalloids exhibit properties intermediate between metals and non-metals for example silicon does not conduct electricity very well at low temperature but shows increased conductivity at high temperature each box in the table gives you important information about the element the symbol for the element the name of the element the atomic number the atomic weight each chemical element in the periodic table has a very well defined neighborhood above and below it has elements with the same distribution of electrons and very similar properties and on its right it has an element that has an electron and one proton more and therefore has different properties [Music] we call it periodic because in this table the elements become similar again periodically tricky part is that the number of electrons filling one layer varies and their distribution follows well-defined rules of quantum chemistry two in the first eight in the second 18 in the third but in two phases [Music] which makes it necessary to distribute the chemical elements in the table in such a weird way but in the end everything makes sense and we have the whole universe in a single table [Music] foreign

Channel: SCIENtrific ADVENTURE

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Keywords: periodictableofelementsexplained, theperiodictableofelements, periodictablegrade8science, periodictableofelementsscience8, partsoftheperiodictable

Id: IZCV05-Pur0

Length: 7min 58sec (478 seconds)

Published: Tue Mar 21 2023