What characteristics do ultrasound waves have?

Ultrasound waves are sound waves with frequencies above the audible range for humans, typically greater than 20 kHz. The correct choice highlights the characteristics of ultrasound waves, specifically their high intensity and small wavelength.

High intensity in this context refers to a stronger amplitude of the sound wave, which allows it to penetrate various materials effectively, making it useful in medical imaging and industrial applications. The small wavelength of ultrasound waves is significant because shorter wavelengths provide better resolution in imaging applications, allowing for clearer pictures of internal structures.

Furthermore, ultrasound waves exhibit limited diffraction due to their short wavelengths. This means that they can maintain their intensity over distance better than longer-wavelength sounds, making them effective for focused imaging. These properties are essential for their use in diagnostic ultrasound, as they enhance the ability to visualize organs and tissues with precision.

The other options describe characteristics that do not accurately align with ultrasound. For example, high intensity and long wavelength is typical for certain types of sound but does not pertain to ultrasound. Similarly, low frequency and high energy is misleading because ultrasound is characterized by high frequency rather than low. Lastly, low intensity in conjunction with small wavelength does not typically apply to ultrasound, which is known for its ability to maintain intensity over distances.