The spectrum of light emitted by helium atoms is different than that emitted by hydrogen atoms because

Answer;

The different atoms have different quantized energy levels

Explanation; The atoms of different elements have different energy levels because they have different nuclear charges and spins, and different numbers of electrons. Each different kind of atom, like hydrogen or radon, has a distinct nuclear charge and number of electrons. This makes the potential energy function different for each atom, and therefore results in different energy levels. In an emmission spectra, each bright band corresponds to a difference between energy levels within the atom.