what are the cheapest reagents to make hydrogen gas?

Question

this question is related to chemistry

Answer 1

Electricity - 12V DC and a dilute solution, say, of salt water, and you can collect hydrogen at the negative electrode.

Answer 2

electrolysis of any aqueous salt solution with inert electrodes like carbon or platinum(expensive).
Make sure the salt is not of transition elements, because instead of H+ going to the cathode, transition elements will go to the cathode since it's less reactive than hydrogen.
Example, you can electrolysis dilute sulphuric acid to obtain hydrogen gas at the cathode, make sure that the test tube collecting the gas is inverted because hydrogen gas is lighter than air.
*Electrolysis of water is possible too*