Answer:
Step-by-step explanation:
Because the alkali metal is really willing to give up its electron much more so than Hydrogen.
The redox reaction looks like this
K ===> K+ + 1 e- The reduction vo is very high which means that the K really does want to give up that electron.
2H+ +2e- ====> H2 The oxidation vo is almost 0 but the Hydrogen is the perfect recipient for the 2 electrons.