Density Why do firemen crawl in smoke filled rooms?
Sublimation Why do mothballs disappear over time?
Ultrasound Why is ultrasound used in sonar?
Refraction of Light Why does a pencil look bent in water?
Stomata Why do water lilies have stomata on the upper side of their leaves?
Frequency Why do women have shriller voices than men?
Diffusion Why can we smell hot food from a distance?
Density Why does an iron nail float on mercury and sink in water?
Earthing Why do buildings have lightning rods?
Rust Why is oxalic acid used to remove rust stains?