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Unformatted text preview: 1 Chapter 2 The Chemical Context of Life Practice Questions Multiple Choice Questions 1) About 25 of the 92 natural elements are known to be essential to life. Which four of these 25 elements make up approximately 96% of living matter? A) carbon, sodium, chlorine, nitrogen B) carbon, sulfur, phosphorus, hydrogen C) oxygen, hydrogen, calcium, sodium D) carbon, hydrogen, nitrogen, oxygen E) carbon, oxygen, sulfur, calcium Answer: D Topic: Concept 2.1 Skill: Knowledge/Comprehension 2) Trace elements are those required by an organism in only minute quantities. Which of the following is a trace element that is required by humans and other vertebrates? A) nitrogen B) calcium C) iodine D) sodium E) phosphorus Answer: C Topic: Concept 2.1 Skill: Knowledge/Comprehension 3) Three or four of the following statements are true and correct. Which one, if any, is false ? If all the statements are true, choose answer E. A) Carbon, hydrogen, oxygen, and nitrogen make up approximately 96% of living matter. B) The trace element iodine is required only in very small quantities by vertebrates. C) Virtually all organisms require the same elements in the same quantities. D) Iron is an example of an element needed by all organisms. E) All of the other statements are true and correct. Answer: C Topic: Concept 2.1 Skill: Knowledge/Comprehension 4) Which of the following statements is false ? A) Atoms of the various elements differ in their number of subatomic particles. B) All atoms of a particular element have the same number of protons in their nuclei. C) The neutrons and protons present in the nucleus of an atom are almost identical in mass; each has a mass of about 1 dalton. D) An atom is the smallest unit of an element that still retains the properties of the element. E) Protons and electrons are electrically charged particles. Protons have one unit of negative charge, and electrons have one unit of positive charge. Answer: E Topic: Concept 2.2 Skill: Knowledge/Comprehension 5) Each element is unique and different from other elements because of the number of protons in the nuclei of its atoms. Which of the following indicates the number of protons in an atom's nucleus? A) atomic mass B) atomic weight C) atomic number D) mass weight E) mass number Answer: C Topic: Concept 2.2 Skill: Knowledge/Comprehension 2 6) The mass number of an element can be easily approximated by adding together the number of __________ in an atom of that element. A) protons and neutrons B) energy levels C) protons and electrons D) neutrons and electrons E) isotopes Answer: A Topic: Concept 2.2 Skill: Knowledge/Comprehension 7) What is the approximate atomic mass of an atom with 16 neutrons, 15 protons, and 15 electrons?...
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This note was uploaded on 04/02/2010 for the course BIO 181 taught by Professor Clark during the Spring '10 term at Mesa CC.
- Spring '10