Final answer:
When hydrogen gas is excited, it emits four individual frequencies corresponding to violet, blue, green, and red colors. These transitions between energy levels in the hydrogen atom can be observed simultaneously as a blended pink color. This phenomenon allows us to see all three colors in hydrogen's spectrum at once.
Step-by-step explanation:
The hydrogen spectrum consists of four individual frequencies - violet, blue, green, and red - that can be observed simultaneously. When hydrogen gas is excited and an electric current is passed through it, the emitted light appears pink due to our eyes blending the four colors. The colors correspond to transitions of electrons between different energy levels in the hydrogen atom.
For example, the transition from the fifth to the second energy level results in the blue color, the transition from the fourth to the second level results in the green color, the transition from the third to the second level results in the red color, and the transition from the sixth to the second level results in the violet color.
Thus, by exciting hydrogen atoms and observing the resulting emissions, we can see all three colors in hydrogen's spectrum simultaneously.