Final answer:
The speed and wavelength of light decrease when it enters glass from air, but the frequency remains unchanged. Refraction causes light to bend towards the normal due to the change in speed in different media.
Step-by-step explanation:
When light enters glass from air, the speed of the light decreases due to the higher refractive index of glass compared to air. According to the equation v = f \(\lambda), where v is the speed of light, f is the frequency, and \(\lambda) is the wavelength, if the speed v decreases and the frequency f remains constant, the wavelength \(\lambda) must also decrease. Therefore, the correct changes that occur are that the speed and the wavelength of the light decrease, but the frequency remains unchanged.
The refractive index of glass is higher than air, which explains why the speed of light is lower in glass. Also, when light enters a denser medium such as glass, it bends towards the normal. This effect is described by Snell's law. So when light travels from air into glass, the ray bends towards the normal (refraction), and the speed decreases. However, the frequency is determined by the original light source and does not change when light enters a different medium.