Question

All alkali metals are solids hur hydrogen is a gas with diatomie
molecules Do you justify the inclusion of hydrogen in first group with
alkall metals​

Answer 1

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Though Hydrogen is placed under Group I A or alkali metals group, it is not an alkali metal. This can be justified by the reasons below:

• Hydrogen have one electron in its outermost shell and s-orbital. That's why, it was placed under this group.

• Hydrogen doesn't forms ionic bonds easily, and mostly can be found forming covalent bonds.

• It is poor conductor of heat and electricity unlike the alkali metals.

• It also shows characteristics of halogens.

Due to these, we cannot consider Hydrogen an alkali metal or a metal more certainly. It is a non-metal but have strange properties.

It is the lightest element known. The total mass of hydrogen atom is that of a proton. Also the electron have high KE due to which it is a gas.

Answer 2

$\rm\huge{Answer :-}$

$\leadsto$ The similarity of hydrogen with alkali metal is ns1 configuration and ability to exhibit +1 oxidation state. Hydrogen, because of its small size and high electronegativity, it is a non-metal with high I.P. It shares one electron with another hydrogen and forms diatomic molecules. Due to weak vander Waals forces of attraction it is a gas whereas in alkali metals, metallic bond is present hence they are solid. Hence, hydrogen can't be included in first group along with alkali metal.

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