List four metals that will mot replace hydrogen in an acid

The four metals that will not replace hydrogen in an acid are Cu, Ag, Au, Hg.

Explanation:

As Copper Cu lies below the hydrogen, this is why it is less reactive and ca not replace Hydrogen from its compound. Silver Ag also lies below the hydrogen and therefore it is less reactive to displace Hydrogen. Gold Au becomes less reactive than Hydrogen due to its placement below Hydrogen acid. Mercury Hg is less reactive than Hydrogen