Introduction: When an electron absorbs a photon, it gains energy. The added energy causes the electron to move to an orbit that is farther from the nucleus. Because each possible orbit is associated with a particular amount of energy, orbits are known as energy levels. By convention, an energy of 0 eV is assigned to the energy level that is infinitely far from the nucleus. (This is done so that atoms of different elements can be compared from a common starting point.) As a result of this convention, each energy level has a negative energy.

Question: How do energy levels relate to the spectrum of hydrogen?

List: Look at the graph of energy levels. List the energy of each level (n = 1, 2, 3, etc.).