A bond formed between a selenium atom and an hydrogen atom is likely to be COVALENT.
Selenium react with hydrogen to form hydrogen selenium. H2Se. The atomic number of selenium is 34 and it has 6 electrons in its outermost shell, which means that, it needs two more electrons to attain the octet form. Therefore, two hydrogen atoms, with one electrons each in their outermost shells share their electrons with selenium in such a way that the three atoms involved have full electrons in their outermost shell. This is a covalent bonding.