#1 Which of the following gases is present under pressure in soft drinks?
Carbon dioxide is present under pressure in soft drinks. Carbon dioxide adds that special sparkle and bite to the beverage and also acts as a mild preservative. Carbon dioxide is an uniquely suitable gas for soft drinks because it is inert, non-toxic, and relatively inexpensive and easy to liquefy.
#2 The substance which does not expand on going from liquid state to solid state is
In printing, type metal (sometimes called hot metal) refers to the metal alloys used in traditional type founding and hot metal typesetting. Lead is the main constituent of these alloys. Antimony and tin are added to make the character produced durable and tough while reducing the difference between the coefficients of expansion of the matrix and the alloy. Pure metal melts and solidifies in a simple manner at a specific temperature. This is not the case with alloys.
#3 The radio-active element used in heart pacemakers is
Pacemakers are used to stimulate a regular heartbeat when the body’s natural electrical pacing system is irregular or not transmitting properly. Over the years, various power sources have been used for pacemakers, including a radioactive material called plutonium-238.
#4 The element which is commonly used in nuclear for producing electricity by nuclear fission is
Uranium is used to produce a chemical and nuclear reaction which makes a lot of heat. This heat is used to turn water into steam, which turns turbines urbines generate electricity.
#5 Table salt gets moist during rainy season because
Table salt is refined salt, which contains about 97 to 99 percent sodium chloride. It usually contains substances that make it free-flowing (anticaking agents) such as sodium aluminosilicate or magnesium carbonate. Because of Hygroscopic nature of salt it
become wet in rainy season as the salt absorbs moisture from environment.