You might have noticed the marking of 500 W on an electrical appliance . What does it indicate ?

During sunset , you might have noticed that the western horizon becomes reddish . Why is it so ?

You might have seen the twinkling of at night. But planets do not twinkle . Why ?

You know what thermoplastics and thermosetting plastics are. You might have noticed that those who collect old plastics do not accept certain type of plastic articles. What are they? What may be the reason for this ?

What does the circle inside the bẹnzene ring indicate?