Is the sunset caused by the scattering light of the atmosphere?

Yes, the sunset is primarily caused by the scattering of sunlight by the Earth's atmosphere. As the sun dips below the horizon, its light passes through a thicker layer of atmosphere, which scatters shorter wavelengths of light (like blue and violet) more than the longer wavelengths (like red and orange). This scattering effect results in the vibrant colors often seen during sunset.