Make a rule if you knew the number of valence electrons in a nonmetal atom, how would you determine the valence of the elment? (hint: ignore hydrogen now.)

Alculate the concentration of h3o⁺in a solution that contains 5.5 × 10-5m oh⁻at 25°c. identify the solution as acidic, basic, or neutral. a) 1.8 × 10-10m, basicb) 1.8 × 10-10m, acidicc) 5.5 × 10-10m, neutrald) 9.2 × 10-1m, acidice) 9.2 × 10-1m, basic

The difference between the atomic number of an element and the element’s atomic mass is the number of ions.

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.