Group 1 Alkali Metals

First group : Alkali metals :: Second group : ___________

On moving down the group of alkali metals, ionization energy ________

On moving down the group of alkali metals, ionization energy ________

On moving down the group of alkali metals, ionization energy ________

On moving down the group of alkali metals, ionization energy ________

Answer the following questions: What do you think? Should hydrogen be placed in the group 17of halogens or group 1 of alkali metals in the modern periodic table?