37. The gas used for filling weather balloons is A.Helium B.Hydrogen C.Air D.Nitrogen
Answer: Option A Solution: A balloon is an inflatable flexible bag filled with a gas, such as helium, hydrogen, nitrous oxide, oxygen, or air. Modern balloons can be made from materials such as rubber, latex, polychloroprene, or a nylon fabric, while some early balloons were made of dried animal bladders, such as the pig bladder. Some balloons are used for decorative purposes, while others are used for practical purposes such as meteorology, medical treatment, military defense, or transportation. A balloon’s properties, including its low density and low cost, have led to a wide range of applications. Because of the non combustible property of the helium gas it is widely used in weather balloons rather than hydrogen gas which is highly combustible.
