Water is a pure substance. Which of the following is true about water? (5 points) a.) Its compounds can only be chemically separated into the elements that make it up.
b.)Its compounds can only be physically separated into the elements that make it up.
c.)It is made up of a variety of compounds, each with a different set of properties.
D.) it is made up of one element and one compound, each with the same properties.

Lab reagent, hypothesis test.a reference solution used as a lab reagent is purported to have a concentration of 5 mg/dl. six samples are taken from this solution and the following concentrations are recorded: (5.32, 4.88, 5.10, 4.73, 5.15, 4.75) mg/dl.these six measurements are assumed to be an srs of all possible measurements from solution.they are also assumed to have a standard deviation of 0.2, a normal distributin, and a mean concentration equal to the true concentration of the solution.carry out a significance test to determine whether these six measurements provide reliable evidence that the true concentration of the solution is actually not 5 mg/dl.