Name two metals which will displace hydrogen from dilute acids, and two metals which will not.

Explanation

Metals such as Mg, Al, Zn, Fe, etc. which lie above hydrogen in the activity series are more reactive than hydrogen and hence can displace hydrogen from dilute acids. For example.
`underset("Zinc")(Zn_((s))) + underset("Sulphuric acid")(H_(2)So_(4(aq)))tounderset("Zinc(II)sulphate")(ZnSo_(4(aq)))+underset("Hydrogen")(H_(2(g)))`
`underset("Iron")(Fe_((s))) + underset("Hydrochloric acid")(2HCl_((aq)))tounderset("Iron chloride")(FeCl_(2 (aq)))+underset("Hydrogen")(H_(2(g)))`
Metals such as Cu, Hg, Ag, Au, etc. Which lie below hydrogen in the activity series are less reactive than hydrogen and hence cannot displace hydrogen from dilute acids.
`Cu, Hg, Ag, Au,` etc. `overset("Dilute acids")to` No reaction