Dominic and Eva are using the same type of stopwatches to measure the time it takes for a chemical reaction to occur. They each use the same stopwatch to measure the time. These are their results:PersonTrial 1Dominic78 secondsEva81 secondsWhy are their results unreliable and can lead to a pseudoscientific claim?They did not repeat their tests multiple times. They used the same type of stopwatch. They did not change the reactants in their chemical reactions. Only one person should have collected the data.

water at room temperature is flowing through a pipe with pressure taps located 10 ft apart along one section of the pipe, which are connected to a mercury (s=13.6) manometer.

the answer is 75.0%.

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.