When a wave transfers from one medium to another with different properties, the following statement is true:
The frequency remains constant.
In wave mechanics, when a wave travels from one medium to another, its frequency does not change. However, its speed and wavelength can change depending on the properties of the new medium. The relationship between speed, frequency, and wavelength is given by the equation:
\[ v = f \lambda \]
where \( v \) is the wave speed, \( f \) is the frequency, and \( \lambda \) is the wavelength. Since the frequency remains constant, any change in speed will result in a corresponding change in wavelength to satisfy this equation.