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Chemistry Forums for Students => Inorganic Chemistry Forum => Topic started by: Aakash on November 26, 2013, 11:36:51 AM

Title: Why does hydrogen form metallic hydride like LiH ?
Post by: Aakash on November 26, 2013, 11:36:51 AM
Why does hydrogen form metallic hydride like LiH when both the metals want to lose electrons?
Title: Re: Why does hydrogen form metallic hydride like LiH ?
Post by: Corribus on November 26, 2013, 03:19:35 PM
You are anthropomorphizing too much.  What makes you think they want to "lose" electrons?
Title: Re: Why does hydrogen form metallic hydride like LiH ?
Post by: Hunter2 on November 27, 2013, 01:19:52 AM
Hydrogen is able to get the noble gas shell from Helium with two electrons. So it is possible to form Hydrids. Like LiH, CaH2, etc.
Title: Re: Why does hydrogen form metallic hydride like LiH ?
Post by: Enthalpy on November 27, 2013, 10:52:19 AM
No atom loses electrons easily, because the resulting positive ion attracts electrons.

An electron transferred from one atom to an other can happen in a strict ionic bond, when one atoms attracts the electron much more than the other does - AND it needs some mechanism to help the resulting ions keep stable.

In a solid, positive ions are closely surrounded by many negative ones (and negative by many positive ones) so that the electric potential of the ions is not too big.

In a polar solvent, liquid molecules put the end of opposite charge near each ion, which again reduces the electric potential.

Other bonds - which can be strong as well - rather put electrons of both atoms on a new common orbital, which can be more favourable than the separate atoms. And since most atoms are already bound in molecules (H2, O2, N2...) a reaction has to break the old molecules first, so it's a mere re-arrangement of the bonds.