Import Question JSON

\text{HINT: Hydrogen resembles both alkali metals and halogens.} \text{Explanation:} \text{The resemblance with alkali metals:} \text{1. Like alkali metals, hydrogen contains one valence electron in its valency shell.} \text{Hence, it can lose one electron to form a unipositive ion.} \text{2. Like alkali metals, hydrogen combines with electronegative elements to} \text{form oxides, halides, and sulphides.} \text{The resemblance with halogens:} \text{1. Both hydrogen and halogens require one electron to complete their octets.} \text{Hence, hydrogen can gain one electron to form a uni-negative ion.} \text{2. Like halogens, it forms a diatomic molecule and several covalent compounds.} \text{Though hydrogen shows some similarity with both alkali metals and halogens,} \text{it differs from them on some grounds.} \text{Unlike alkali metals, hydrogen does not possess metallic characteristics.} \text{On the other hand, it possesses a high ionization enthalpy.} \text{Also, it is less reactive than halogens.} \text{Owing to these reasons, hydrogen cannot be placed with alkali metals} \text{(group I) or with halogens (group VII).} \text{In addition, it was also established that } \text{H}^{+} \text{ ions cannot exist freely} \text{as they are extremely small. } \text{H}^{+} \text{ ions are always associated with} \text{other atoms or molecules.} \text{Hence, hydrogen is best placed separately in the periodic table.}