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

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

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 ?

You might have observed the bubbles of steam coming from bottom of vessel when water is heated.These bubbles disappear as it reaches top of liquid just before boiling and they reach the surface at the time of boiling.Explain the reason.

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