My chemistry teacher said Hydrogen when bonded with metals, shows Oxidation state of -1 except CuH. In CuH, Hydrogen has oxidation state of +1 & Copper has -1. But on the internet, it is showing that Hydrogen has oxidation state of -1 in CuH too. I am confused which one is correct. If Hydrogen has Oxidation state of +1 in CuH, why is it so? Thanks