Applying the bohr model to a triply ionized beryllium atom (be3+,z=4), find the ionization energy required to remove the final electron in be3+.

What mass of iron must be in a hot pack to provide -335kj of heat when the iron reacts with oxygen and is converted to iron (111) oxide according to the following thermochemical equation? 2fe(s) + 1.5o2(g)—> fe2o3(s) delta h= -824.2kj/mol