Yara is the world's leading manufacturer and trader of ammonia. A chemist in training at Yara wants to create ammonia, NH3, on a small scale. How much ammonia could be produced by the reaction of 3.0 g of nitrogen with 1.0 g of hydrogen? N2 (g) + H2 (g) → NH3 (g) (not balanced)

Ans. : frostbite is when exposure to cold temperatures causes freezing to the skin or other tissues. it most commonly affects the hands, feet, and face. the longer areas are exposed to cold, typically the worse the frostbite. the water temperature used for rewarming a frostbitten part should be : (102 -105) f degrees.

Heat is involved in chemical change in two ways; chemical changes either result in heat being added to or removed from an object, and chemical changes require a certain amount of heat before they can take place.

The answer is d- principle of faunal succession.