Question

Frank and Lisa are analyzing the chart, which shows the speed at which light travels through different media.

A 2 column table with 4 rows with the column on the left labeled medium with entries water, air, glass, diamond. The column on the right is labeled speed of light in meters per second and are all times 10 Superscript 8 Baseline with entries 2.25, 2.99, 1.97, 1.24.
Frank says that light travels through diamond with the greatest frequency. Lisa says that light travels through air with the greatest frequency.

Which best describes the accuracy of these statements?

Frank is correct because light travels through diamond at the slowest speed, and speed and frequency have an inverse relationship.
Lisa is correct because light travels through air at the fastest speed, and speed and frequency have a direct relationship.
Neither person is correct because light does not change frequency when it travels through different media.
Both people are correct because light has both an inverse and a direct relationship with frequency, depending on the media.

Answer 1

Neither person is correct. Frequency stays the same when light passes between media — the speed and wavelength change, but the frequency is determined by the source (v = f·λ, so λ changes when v changes).