In the activity series of metals, which metal(s) will displace hydrogen from an acid?

Above is a picture of the metal reactivity series. Notice that Potassium - Lead are above Hydrogen and are leaning towards the most reactive end of the scale. Copper - Gold are below Hydrogen and lean to the least reactive end.

All of the elements above Hydrogen in the reactivity series will displace Hydrogen atoms from an acid during a reaction. This is because they are higher in the series than Hydrogen, hence more reactive than Hydrogen, so they will be able to displace it from its compound.

This displacement is not only true for Hydrogen, but for all the metals in the series. Once a metal is above another in the series, it is more reactive than it and will be able to displace it from its compound.

For example, Iron will displace Lead from its compound but Iron cannot displace Zinc from its compound. The latter is true because Iron is lower than Zinc in the series, hence it is less reactive so it won't be able to displace Zinc from its compound.

Here is a video which shows an experiment to determine the activity of three metals.