[Music] in order to systematically organize All the known elements scientists use the periodic table it's an arrangement of elements in which the elements are separated into groups based on a set of repeating properties a periodic table allows you to easily compare the properties of one element or a group of elements to another element or group of elements the periodic table is organized into rows which are called period or series and columns that are called groups or families and just like a grer organizes produce by similar characteristics chemists use the properties of elements to sort them into groups the first chemist to do this was Mev he sorted The Elements by their atomic mass the problem was that the masses of some elements were so similar that it wasn't a good way to differentiate them the modern periodic table is sorted by increasing atomic number which leads us to periodic law when elements are arranged in order of increasing atomic number there is a periodic repetition of their physical and chemical properties in order to make a more compact periodic table one section of elements is removed from the middle and placed underneath metals are on the left side of the staircase non-metals are on the right side and metalloids are directly along the staircase and that staircase just helps us locate the metalloids metals are good conductors of heat and electric current they have high luster and Sheen they're reflective solids at room temperature except for mercury and many are ductile and malleable non-metals are poor conductors of heat and electric current except for carbon and they're brittle metalloids are similar to both metals and non-metals and can have a mix of both properties for example silicon is a poor conductor of current but can be cut wa for thin there are a few important family names to know on the periodic table as well the First Column is the alkaline metals which all explode in water and make cat ions column 2 the alkaline earth metals also make cat ions column 17 are the halogens which form annion and 18 is the noble gases also known as the inert gases they don't react with other elements unless they're put into some very extreme conditions there are also some general regions of the periodic table the representative elements are the ones we use most often the transition medals are the Block in the middle of the representative elements and the inner transition medals are usually pictured beneath the transition medals thanks for watching this episode of teachers pet don't forget to like And subscribe and follow me on Twitter at science pet