Name the waves that are often refered to as Heat Waves. Name the physical quantity that has a lower, higher and same valuefor these waves as compared to its value for x rays

Infrared rays are often referred to as heat waves.

Infrared means 'below red' . So they appear in the spectrum below visible red light since their frequency is just smaller than that of red light. Infrared rays have lower frequency than X-rays.

Infrared rays have higher wavelength compared to X-rays. Wavelength of em waves is inversely proportional to frequency.[Wavelength = Velocity of wave / frequency]

Infrared rays travel with the same speed as X-rays. In vacuum all electromagnetic waves travel with the velocity of light.