Yes, when a sound wave travels from air to water, the wavelength of the wave changes. The change in wavelength is a result of the difference in the speed of sound between the two mediums.
In general, sound waves travel faster in water compared to air. The speed of sound in air is approximately 343 meters per second at room temperature, while in water, it is around 1482 meters per second. As the speed of sound is directly proportional to the wavelength, an increase in speed leads to an increase in wavelength, and vice versa.
When a sound wave transitions from air to water, the wavefronts of the wave undergo a change in speed, causing them to bend or refract. As a result, the wavelength changes while the frequency remains constant. According to the equation v = f * λ, where v is the speed of sound, f is the frequency, and λ is the wavelength, the wavelength will increase as the speed increases when transitioning from air to water.
In summary, when a sound wave travels from air to water, the wavelength of the wave changes due to the difference in the speed of sound between the two mediums.