Wwhat do these substances have in common? apple juice helium gas salt water copper wire a. they are composed of atoms. b. they are pure substances. c. they are composed of molecules. d. they are compounds.

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.

Correct relationship between molecular formula and empirical formula

Which sample at stp has the same number of atoms as 18 liters of ne at stp