The long form of modern periodic table consists of seven rows called periods and eighteen columns called groups. Periods: * Each period starts with an alkali metal and ends with an inert gas element. Features of the long form periodic table. (a) First period contains 2 element, and is called shortest period. (b) Second and third periods contains 8 elements each, and are called Short periods. (c) Fourth and fifth periods contain 18 elements each, and are called long periods. (d) Sixth period contains 32 elements. The modern periodic table is sometimes expanded into its long or column form by reinstating the footnoted f-block elements into their natural position between the s- and d-blocks. Unlike the column form this arrangement results in "no interruptions in the sequence of increasing atomic numbers". .
The Periodic Table: Crash Course Chemistry #4, time: 11:22Tags:Tvants new version 2012 chevy,Fairy tail ep 163 eng sub er,Citrix receiver hdx flash redirection,Tant besoin de toi instrumental s