Question 5 A A 5.0 g sample of MgCl, may contain measurable amounts of other compounds as impurities. Which of the following quantities is (are) needed to determine that the sample is pure MgCl,?
The color and density of the sample
The mass of Mg in the sample only
The number of moles of Cl in the sample only
The mass of Mg and the mass of Cl in the sample

Which of the following is not a good technique for managing used oil? a) have specific, labeled catch pans available for technicians who are collecting oil b) spills in your shop and any releases on pavement or outside should be poured down a drain c) do not use oil containers for antifreeze or other non-similar fluids d) be prepared for oil spills with the proper absorbents

The half-life of a certain element is 100 days. how many half-lives will it be before only one eighth of this elementremains?

Four statements about the development of the atomic model are shown below. a: electrons have wavelike properties. b: atoms have small, negatively charged particles. c. the center of an atom is a small, dense nucleus. d: atoms are hard, indivisible spheres. which order of statements represents the historical development of the atomic model? c-d-a-b c-d-b-a d— в-а — с d-b-c-a