Hydrogen
This is the lightest of all elements. It is a colorless and odorless gas, which is very flammable. The gas is non-toxic.
Hydrogen gas cannot easily be purchased by the general public, but it can be made easily at home. The most convenient way is to take some small pieces of magnesium ribbon or turnings and put these in dilute hydrochloric acid with approximately 5% hydrogen chloride by weight. A vigorous reaction occurs. The gas produced is pure hydrogen. The same also works with zinc and aluminium, but these react more slowly and aluminium also has a certain induction period in which its protective oxide layer is dissolved.
Hydrogen can also be made by electrolysis of water. A suitable setup is to use a solution of table salt with a simple copper wire as cathode and an iron wire as anode. At the cathode, hydrogen is formed. The anode dissolves. It is better to use an iron anode instead of a copper anode, because of environmental concerns. Copper waste should be handled as chemical waste.
Hydrogen as a gas
can be used for nice detonating gas demonstrations, by mixing it with
oxygen in
the ratio volume(H2) : volume(O2) = 2 : 1. This reaction
is dangerous however, and only small bubbles of gas of at most a few ml should
be used. The bangs are really loud!
The main importance of hydrogen for the home chemist is as active constituent in acids. Many experiments require the use of acids and as such, the element hydrogen frequently plays an important role in many experiments.
A special form of hydrogen, called deuterium, with an added neutron in the nucleus is also available commercially in the form of 'heavy water'. Although this can be purchased by the general public, there is no reason to buy this for a nice home lab. Heavy water is not really different from ordinary water and as such does not add anything new.