The Bohr model can be accurately applied to a singly ionized helium atom. This atom has two protons in the nucleus (Z = 2) and a single electron orbiting the nucleus. When the electron makes a transition from a higher energy level to the n = 4 level, some of these transitions produce light in the visible part of the electromagnetic spectrum (about 380 nm to 750 nm). Determine which of these transitions correspond to these visible lines.