Wikipedia -- Earth:
Mean radius = 6,371.0 km
Mass = 5.9736 × 10^24 kg
Mean density = 5.5153 g·cm−3
Wikepedia -- Iron:
Density (near r.t.) = 7.874 g·cm−3
Liquid density at m.p. = 6.98 g·cm−3
...at pressures close to those at the center of the Earth (3.2 to 3.4 million atmospheres)..., hydrogen is still not a true alkali metal, because of the non-zero band gap.
The density of liquid Hydrogen at 20K is only 0.07 g·cm−3
The density of solid Hydrogen, I cannot find (yet), but is unlikely to be greater than 10 times the density of LH2. So, let's assume worst case, and call it 0.7 g·cm−3
Allow that about 1/2 (or more) of the Earth's volume is a variety of solid and liquid rocks, like basalt at 3.0 g·cm−3.
To achieve an average density for the whole planet of 5.5 g·cm−3,
the core of the planet needs a density between 7 and 8 g·cm−3
The density of Iron (depending on phase and pressure) is between 7 and 8 g·cm−3
There is NO CHANCE at all that Hydrogen, in ANY form, at ANY pressure, could be more than 0.7 g·cm−3, and therefore could constitute the bulk of Earth's core. It would have to be at least 10, and probably 20 or 25, TIMES DENSER.
NO CHANCE. NO WAY. The Earth's core is not Hydrogen. It is Iron.
And NO, we do not need another thread on this very silly, stupid subject. It has all been said before. We've gone over the numbers and the physics until we're numb. Every claim of Core=Hydrogen has been easily and trivially debunked.
