Can hydrogen gas be solidified

Answer 1

Though at the top of the alkali metal column in the Periodic Table, hydrogen is not, under ordinary conditions, an alkali metal. In 1935 however, physicists Eugene Wigner and Hillard Bell Huntington predicted that under an immense pressure of ~25 GPa (250,000 atm or 3,500,000 psi), hydrogen atoms would display metallic properties, losing hold over their electrons. Since then, metallic hydrogen has been described as "the holy grail of high-pressure physics".

The initial prediction about the amount of pressure needed was eventually proven to be too low. Since the first work by Wigner and Huntington the more modern theoretical calculations were pointing toward higher but nonetheless potentially accessible metallization pressures. Techniques are being developed for creating pressures of up to 500 GPa, higher than the pressure at the center of the Earth, in hopes of creating metallic hydrogen.

Answer 2

Yes, hydrogen gas can be solidified at very low temperatures (-259.16°C or 13.99 K). At this temperature, hydrogen gas turns into a solid state known as solid hydrogen or molecular hydrogen (H2).