Periodic table is unquestionably one of the most fundamental but very important tools of the entire chemistry. Understanding of periodic table & various trends help us in virtually all aspects of chemistry. Difference in electronegativity amongst the elements plays very important role in the type of chemical bonding viz, ionic or covalent. Ionization energy trend also helps us in deciding the reactivity of an element or strength of the chemical bond in the given compound. Interestingly ionization energy depends on the atomic radius as well. Electronegativity trend guides us in determining shape & geometry of the molecules as well as solubility in the given solvents since it determines if the given compound is polar or non-polar Periodic table provides a guideline in selection of suitable catalyst for the given reaction e.g. d block elements / transition metals. Electrochemistry revolves around reactivity of the given set of elements involving redox reactions which again can be understood using periodic table. We study chemical reactions of group 1 elements (also known as alkali metals) as well as group 17 (halogen elements), elements belonging to both these groups being highly reactive. It is very difficult even to visualize, learning chemistry without using periodic table.