atomic energy levels are like rows in a parking lot

An example of a teaching analogy:

"Parking lot rows are analogous to the energy levels in an atom in the following ways:

• Different numbers of electrons are found in different energy levels. Similarly, not all rows will hold the same number of cars, depending on the location and shape of the rows.
• The energy levels, generally speaking, fill from the nucleus outwards. Similarly, the arena in which the basketball or hockey game is being played, represents the nucleus of the atom. The parking lot rows that are closest to the arena are always the ones which get filled up first, and the farther away ones later.
• The ionisation energy of an electron in an outside energy level is smaller than for an electron in an inner level. Similarly, a car parked on an outer row of the parking lot can generally get out of the lot easier after the event, than a car located in one of the congested inner rows, closer to the arena (nucleus)."

Source: Murray Hart, retired science teacher, previously posted at scienceanalogies.com

Read about analogy in science

Read examples of scientific analogies

Many examples of science analogies are listed in 'Creative comparisons: Making science familiar through language. An illustrative catalogue of figurative comparisons and analogies for science concepts'. Free Download.