a How does the atomic size vary on going down from top to bottom in a group of the periodic table Wh...

Question

a How does the atomic size vary on going down from top to bottom in a group of the periodic table Why does it vary this way b Lithium sodium and potassium are all metals that react with water to liberate hydrogen gas Is there any similarity in the atoms of these elements Explain your answer

Accepted Answer

a The main characteristic of the last elements in a period is that they all have 8 valence electrons in their atoms except helium Such elements are generally called noble elements which have stable electronic configurations b The similarity between Lithium Sodium and Potassium are They have only one valence electron in their outermost shells making them extremely unstable As a result they easily react with water to produce hydrogen They are also called alkali metals

Lakhmir Singh Solutions Class 10 Chemistry Solutions for Exercise in Chapter 5 - Chapter 5 Periodic Classification of Elements