Chapter 6 of the Kerala SCERT textbook for Physics class 10 is all about “Light - Reflection and Refraction”. Here are the main ideas from this chapter, presented in a way that is suitable for a pupil aged ten:

1. Light is a form of energy that travels in straight lines and can be reflected and refracted.
2. Reflection is when light bounces off a surface and changes direction. The angle of incidence (the angle at which the light hits the surface) is equal to the angle of reflection (the angle at which the light bounces off the surface).
3. Mirrors are surfaces that reflect light and can be used to form images. There are two types of mirrors: plane mirrors and curved mirrors.
4. Refraction is when light bends as it passes through a medium (such as air, water, or glass) with a different density. The amount of bending depends on the angle of incidence and the refractive index of the medium.
5. Lenses are curved surfaces that refract light and can be used to form images. There are two types of lenses: convex lenses and concave lenses.
6. The human eye uses lenses to focus light onto the retina, which sends signals to the brain to form an image.
7. The speed of light is constant in a vacuum, but it can be slowed down in a medium with a higher refractive index.
8. Total internal reflection is when all the light is reflected back into a medium because the angle of incidence is greater than the critical angle. This phenomenon is used in fiber optics to transmit information over long distances.
9. Applications of reflection and refraction include mirrors, lenses, microscopes, telescopes, and optical fibers.

Overall, this chapter teaches pupils about the properties of light and how it interacts with different surfaces and mediums. It also introduces them to some of the practical applications of reflection and refraction in everyday life.