Question

why is hydrogen called both a metal and a non metal?

Answer 1

Hydrogen is called as metal as some of its characteristics resemble with elements of group 1 which are metals. Some of which are shown below:

1. Electronic configuration: Hydrogen has one electron in the valence shell like metals (group1).

H (Z=1): K¹

Li (Z=3): K², L¹

Na (Z=11): K², L⁸, M¹

2. Just like metals, hydrogen combines with elements like oxygen ,halogens etc to form compounds of similar formulae.

HCl H₂O

NaCl Na₂O

Hydrogen is called as non-metal as some of its characteristics resemble with group 17 elements(halogens) which are non-metals. Some which are shown below:

1. Electronic configuration: Just like halogens, hydrogen needs one electron to attain the duplet configuration of nearest noble gas that is helium.Due to which it gains one electron to become an anion just like halogens.

H (Z=1): K¹

F (Z=9): K², L⁷

Cl (Z=17): K², L⁸, M⁷

2.Atomicity: Like halogens, hydrogen also exists in a diatomic state. The atomicity of hydrogen as well halogens is two.

3.Combination with metals: Just like halogens, hydrogen also combines with metals to form salts with similar formulae.

NaH LiH CaH₂

NaCl LiCl CaCl₂