SSC Chemistry

Chemistry Periodic Table: Purpose and Basic Idea A table that organises elements so similar elements stay together. Study card → Chemistry Historical Development of the Periodic Table From Lavoisier to Moseley, scientists gradually improved the arrangement of elements. Study card → Chemistry Periods, Groups and Table Layout Periods are horizontal rows; groups are vertical columns. Study card → Chemistry Finding Period from Electronic Configuration The highest principal energy level tells the period number. Study card → Chemistry Finding Group from Electronic Configuration Group number depends on outer s, p or d electrons. Study card → Chemistry Electronic Configuration as the Basis of Periodicity Similar outer-shell configuration gives similar chemical behaviour. Study card → Chemistry Exceptions in the Periodic Table Hydrogen, helium, lanthanides and actinides need special attention. Study card → Chemistry Metallic Character, Non-metallic Character and Atomic Radius Across a period metallic character decreases and atomic radius generally decreases. Study card → Chemistry Ionization Energy, Electron Affinity and Electronegativity These trends explain how atoms lose, gain or attract electrons. Study card → Chemistry Special Group Names and Similar Chemical Properties Group names help remember behaviour: alkali metals, halogens, noble gases and more. Study card →