Thus K must be a group 4 element, unknown to mankind or is just a code-name for a known element. If that's true, it's just another analogue of Methane, like Silane (Silicon tetrahydride), Germane (Germanium tetrahydride) and Stannane (Tin tetrahydride). It's also possible that as K is code-name for another element other than Potassium, the H is also a code-name for another element other than Hydrogen. It would be very confusing and complicated if that's the case...