AP Bio-Exam 2 Questions and Answers

AP Bio-Exam 2 Questions and Answers The four most common elements in living organisms include all except: a. hydrogen b. nitrogen c. sodium d. carbon e. oxygen c. sodium Which of the following statements best describes a compound? a. A compound is a pure element. b. A compound contains two or more different elements in a fixed ratio. c. A compound is exemplified by sodium. d. A compound is a solution b. A compound contains two or more different elements in a fixed ratio. The atomic number of an element is determined by the number of: a. electrons b. protons c. neutrons d. ions b. protons When full, the innermost electron shell of neon (atomic number = 10) contains ________ electrons, and the outermost shell contains ________ electrons. a. 2 . . . 8 b. 8 . . . 2 c. 5 . . . 5 d. 0 . . . 10 a. 2 . . . 8 A covalent bond is made when atoms: a. donate electrons b. take electrons c. share electrons d. share protons e. explode c. share electrons What change is occurring in this figure? a. Chlorine is losing an electron. b. Sodium is becoming negatively charged. c. Sodium is filling its third electron shell. d. Chlorine is filling its third electron shell. d. Chlorine is filling its third electron shell. In a water molecule, hydrogen and oxygen are held together by a ________ bond ( be careful!). a. double covalent b. nonpolar covalent