Which of the following statements about the atom is false? a. each atom has a tiny nucleus at its center. b. all the protons and neutrons are located in the nucleus. c. electrons travel in definite circular pathways around the nucleus. d. all atomic nuclei are positively charged.

You have 125g of a certain seasoning and are told that it contains 76.0 g of salt what is the percentage of salt by mass in this seasoning

How many moles of magnesium is 3.01 x10^22 atoms of magnesium?

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.