How does the structure of each passage help determine the content of the passage? a. Passage I contains a character study, but Passage 2 focuses more on concepts.

b. Passage 2 contains significant cultural information, but Passage 1 illustrates history.

c. Passage 1 explains a scientific phenomenon,
but Passage 2 is purely fictional.

d. Passage 2 describes ongoing action, but
Passage 1 focuses more on feelings.

Which statement best describes the oxidation numbers of the atoms found in magnesium chloride? a. magnesium has a 2- oxidation number and chlorine has a 1+ oxidation number. b. magnesium has a 2- oxidation number and chlorine has a 2+ oxidation number. c. magnesium has a 2+ oxidation number and chlorine has a 1- oxidation number. d. magnesium has a 1+ oxidation number and chlorine has a 1- oxidation number.

15. which of the following is not human-caused groundwater pollution? a. water in an aquifer dissolves elements such as arsenic and mercury from surrounding rock. b. water in an aquifer is contaminated by leachate that seeps into the ground from a landfill. c. water in an aquifer becomes polluted with chemicals used in hydraulic fracturing, or fracking. d. water in an aquifer absorbs harmful bacteria from the drainage field of a septic tank.

What is a substance? a. a physical property of matter b. a chemical property of matter c. an element or compound that cannot be physically separated d. characteristics used to tell the difference between mixtures