What is meant by an exothermic reaction?
An exothermic reaction is a chemical reaction that produces heat. AIRSHIPS WERE ONCE FILLED WITH HYDROGEN BUT NOW HELIUM IS USED INSTEAD. WHY IS THE NOBLE GAS HELIUM MORE SUITABLE THAN HYDROGEN? Hydrogen reacts explosively with oxygen in the air, if a spark is provided. Helium, being a noble gas, is very unreactive and so it is much safer to use. BEE STINGS ARE ACID. WHY IS IT POSSIBLE TO SOOTHE A BEE STING WITH BAKING SODA (SODIUM BICARBONATE)? Sodium bicarbonate is a mild alkali. It reacts with the acid in the sting, neutralising it. ACID RAIN CAUSES BUILDINGS MADE OF LIMESTONE TO WEAR AWAY. WHICH GASES ARE RESPONSIBLE FOR INCREASING THE ACIDITY OF RAINWATER? Sulphur dioxide and nitrogen oxides. PLASTIC WASTE IS NON-BIODEGRADABLE: IT IS BETTER TO RECYCLE PLASTIC WASTE THAN TO PLACE IT IN LANDFILL. WHAT IS MEANT BY NON-BIODEGRADABLE? Non-biodegradable describes a material that will not be broken down easily by micro-organisms. This means that plastics placed in landfill will remain th
