AP Chemistry Practice Questions with correct answers

Which one of the following statements concerning matter is correct? a) a gas has a fixed volume but not a rigid shape b) a liquid has a fixed volume and a rigid shape c) a liquid takes on both the volume and the shape of its container d) a solid has a fixed volume and a rigid shape e) both b and d are correct CORRECT ANSWER d All of the following statements are true EXCEPT a) of the 113 known elements, 91 occur naturally b) an element cannot be broken down into two or more pure substances c) a compound is a substance that contains two or more elements d) a pure compound always contains the same elements in the same mass percentages e) another name for a heterogeneous mixture is a solution CORRECT ANSWER e Which term best describes table salt (NaCl) at room temperature? a) gas b) element c) compound d) homogeneous mixture e) heterogeneous mixture CORRECT ANSWER c All of the following statements are false EX