AntiHydrogen

Anti-Hydrogen, dangerous matter which will react with normal matter, if touched normal matter, it will blast and create energy, it has a energy convert rate of %100 ( no energy loss ).

do not add it to normal matter period table, it is in antimatter period table.

can be made with particle accelerator

could be stored if use magnetic force

it does not have isotype, or just not discovered

get more information at https://en.wikipedia.org/wiki/Antimatter