Hydrogen gas (H") can be found in trace amounts in Earth's atmosphere. Which of those statements describes a physical property of hydrogen?

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.

In salt water solution,the salt is the blank

Which of the following has expanded our knowledge of the universe beyond our solar system the most? a. manned space travel b. the hubble space telescope c. the pioneer and voyager missions d. the international space station