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Concept 4.1-4.2 Review 1 A __________ is a substance containing two or more elements that are chemically combined in a fixed ratio. A B C D 2 If a neutral atom contains 15 protons, then it must also contain 15 neutrons. A B 3 protons neutrons electrons both A and B The unique properties of an element are determined by its atomic structure. A B 8 True False Which of the following is normally found outside the nucleus of an atom? A B C D 7 7 14 21 28 Noble gases are very stable because their outermost electron energy levels contain the maximum number of electrons that those outermost energy levels can possess. A B 6 protons and neutrons. protons and electrons. electrons and neutrons. only one subatomic particle is charged. A neutral atom has 14 electrons and 14 neutrons. What is its atomic number? A B C D 5 True False Two electrically-charged subatomic particles are A B C D 4 mixture organism compound trace element True False Neutral atoms of carbon-12 and carbon-14 have A B C D the same number of protons. the same number of neutrons. the same number of electrons. both A and C 8/28/2013 11:04:56 AM Page 1 Concept 4.1-4.2 Review 9 Matter is anything that occupies space and has mass. A B 10 carbon, calcium, nitrogen, helium. carbon, hydrogen, water, nitrogen. carbon, hydrogen, nitrogen, oxygen. carbon, hydrogen, phosphorus, potassium. Which of the following statements about trace elements in your body is TRUE? A B C D 15 True False The four most common elements found in living things are A B C D 14 14 16 28 30 Most of the mass of an atom is concentrated in the electron cloud. A B 13 they can damage parts of living cells. they emit radiation in the form of matter and energy. their nuclei break down over time, giving off radiation. scientists can use them to trace what happens to different atoms within organisms. An isotope has 14 protons and 16 neutrons. What is the mass number of this isotope? A B C D 12 True False Radioactive isotopes are useful in biological research because A B C D 11 Page 2 Trace elements vary from person to person. Nitrogen is an important trace element in your body. Trace elements make up less than 0.01 percent of your body mass. Even by eating a balanced diet, you would not be able to obtain any of the trace elements your body needs. The atomic number, which defines the identity and specific properties of an element, refers to A B C D the number of protons in the atom. the number of neutrons in the atom. the number of electrons in the atom. the mass of the nucleus of the atom. 8/28/2013 11:04:56 AM Concept 4.1-4.2 Review 16 Anything that occupies space and has mass is known as a compound. A B 17 A compound is made of two or more elements chemically combined in a fixed ratio. A B 18 True False On the periodic table, the element sodium is represented by the symbol "S." A B 20 True False The second energy level of an atom can hold up to 8 electrons. A B 19 True False True False The elements Calcium (Ca), phosphorus (P), potassium (K), sulfur (S), sodium (Na), Chlorine (Cl), and Magnesium (Mg) account for approximately ______ of your body mass. A B C D 4% 28% 65% 96% 8/28/2013 11:04:56 AM Page 3 Concept 4.1-4.2 Review Page 4 Answer Key : Concept 4.1-4.2 Review Question: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 8/28/2013 11:04:56 AM Answer C B B B A C A D A D D B C C A B A A B A