What Are Atoms Made Of - Answer Key 3

Item 13 You may want to reference (Page) Section 2.4 while completing this problem. Part A Identify the group 4A element in period five. Express your answer as a chemical symbol. ANSWER: Correct Part B Identify the group 6B element in period four. Express your answer as a chemical symbol. ANSWER: Correct Groups are vertical columns and periods are horizontal rows. The periodic table has eighteen groups and seven horizontal rows called periods. You can see this visually by accessing the periodic table through the resources menu. The periods are listed as 1 to 7 on the left for each horizontal row. The groups are listed at the top over each column, with the default using the American convention. In this convention, elements are organized into groups, indicated with numbers (1 to 8) and letters (A and B). Main group elements are in groups 1A to 8A, while the transition metal elements are in groups 1B to 8B. Inner transition elements are separately placed at the bottom of the periodic table. Item 14 The six metalloids are boron , silicon , germanium they appear with respect to metals and nonmetals. Part A Give the number in Periodic Table for boron Express your answer as a signed integer. ANSWER: 5 Correct Part B Give the number in Periodic Table for silicon Express your answer as a signed integer. ANSWER: 14 Correct Part C Give the number in Periodic Table for germanium Express your answer as a signed integer. , arsenic , antimony , and tellurium . Locate them in the periodic table, and tell where ANSWER: 32 Correct Part D Give the number in Periodic Table for arsenic Express your answer as a signed integer. ANSWER: 33 Correct Part E Give the number in Periodic Table for antimony Express your answer as a signed integer. ANSWER: 51 Correct Part F Give the number in Periodic Table for tellurium Express your answer as a signed integer. ANSWER: 52 Correct Part G Tell where these metalloids appear with respect to metals and nonmetals. ANSWER: on a diagonal boundary before metals on a diagonal boundary between metals and nonmetals on a diagonal boundary after nonmetals Correct Item 15 You may want to reference (Page) Section 2.5 while completing this problem. Locate each element in the periodic table. Indicate which categories apply to each: (i) metal, (ii) nonmetal, (iii) transition element, (iv) main group element, and (v) noble gas. Part A Indicate which categories apply to radon. Check all that apply. ANSWER: nonmetal main group element transition element noble gas metal Correct Radon belongs to group 8A in the periodic table and is a poor conductor of heat and electricity. Therefore, the following categories apply to this element: Main group element: Main group elements are groups numbered 1A through 8A. The letter “A” in the group number signifies main group elements. Noble gas element: These are group 8A elements and the group includes seven elements, namely, helium ( ), neon ( ), argon ( ), krypton ( ), xenon ( ), radon ( ), and element 118 (temporarily named ununoctium [ ]). Nonmetal: Nonmetals are poor conductors of heat and electricity. They are placed in the upper right portion of the periodic table. Part B Indicate which categories apply to cesium. Check all that apply. ANSWER: metal nonmetal transition element main group element noble gas Correct Cesium belongs to group 1A in the periodic table. It is found in the one of the first two groups at the left of the periodic table. It is a good conductor of heat and electricity. Therefore, the following categories apply to this element: Main group element: Main group elements are groups numbered 1A through 8A. The letter “A” in the group number signifies main group elements. Metal: Metals are malleable with a lustrous appearance. They are also a good conductor of heat and electricity and are placed to the left and bottom of the periodic table. Part C Indicate which categories apply to nitrogen. Check all that apply. ANSWER: metal nonmetal transition element main group element noble gas Correct Nitrogen belongs to group 5A, found in the upper right portion of the periodic table. It is a poor conductor of heat and electricity. Therefore, the following categories apply to this element: Main group element: Main group elements are groups numbered 1A through 8A. The letter “A” in the group number signifies main group elements. Nonmetal: Nonmetals are poor conductors of heat and electricity. They are placed in the upper right portion of the periodic table. Part D Indicate which categories apply to cobalt. Check all that apply. ANSWER: metal nonmetal transition element main group element noble gas Correct Cobalt belongs to group 8B, found in the middle of the periodic table. It is a good conductor of heat and electricity. Therefore, the following categories apply to this element: Transition element: Transition elements are groups numbered 1B through 8B. Metal: Metals are malleable with a lustrous appearance. They are good conductors of heat and electricity and are placed to the left and bottom of the periodic table. Item 16 Identify the elements whose nuclei are shown below. For each, tell its group number, its period number, and whether it is a metal, nonmetal, or metalloid. Part A Identify the elements whose nuclei are shown below. Express your answers as chemical symbols separated by a comma. ANSWER: Correct Part B For oxygen, tell its group number. ANSWER: 6A Correct Part C Tell its period number. ANSWER: 2 Correct Part D Is it a metal, nonmetal, or metalloid? ANSWER: metal nonmetal metalloid Correct Part E For sodium, tell its group number. ANSWER: 1A Correct Part F Tell its period number. ANSWER: 3 Correct Part G Is it a metal, nonmetal, or metalloid? ANSWER: metal nonmetal metalloid Correct Item 17 Part A How many electrons are present in an atom in which the first and second shells and the Express your answer as an integer. ANSWER: 12 Correct Part B Name the element. Spell out the full name of the element. ANSWER: magnesium subshell are filled? Correct Item 18 Part A Identify the atom with the following orbital-filling diagram. Express your answer as a chemical symbol. ANSWER: Correct Item 19 Part A For an atom containing 33 electrons, identify the incompletely filled subshell. ANSWER: 4s 4p 4d 3p Correct Part B Identify the way electrons fill the subshells of 4p orbital. ANSWER: Correct Item 20 Part A Identify the group number for the elements indicated in red in the following periodic table. ANSWER: 6A Correct Part B Write the general valence-shell configuration (for example, for group 1A elements). Express your answer as a string without blank space between orbitals. For example, the electron configuration of group 1A elements could be entered as ns^1. ANSWER: ns^2np^4 Correct Item 21 Draw the complete electron configuration for the following elements: Part A Use the buttons at the top of the tool to add orbitals in order of increasing energy, starting at the bottom with the lowest energy orbitals. Click within an orbital to add electrons. ANSWER: This content requires Adobe Flash Player 10.0.0.0 or newer. Correct Part B Use the buttons at the top of the tool to add orbitals in order of increasing energy, starting at the bottom with the lowest energy orbitals. Click within an orbital to add electrons. ANSWER: This content requires Adobe Flash Player 10.0.0.0 or newer. Correct Part C Use the buttons at the top of the tool to add orbitals in order of increasing energy, starting at the bottom with the lowest energy orbitals. Click within an orbital to add electrons. ANSWER: This content requires Adobe Flash Player 10.0.0.0 or newer. Correct Item 22 You may want to reference (Page) Section 2.8 while completing this problem. Part A Identify the group in which all elements have the valence-shell configuration . ANSWER: The elements are in group . 2A Correct The valence-shell configuration indicates the number of electrons present in the outermost shell of an element. The periodic table organizes the elements such that those in the same group have a similar valence-shell configuration. For example, an element with five valence electrons belongs to group 5A. These five valence electrons are filled such that the first two electrons occupy the s subshell and the next three electrons occupy the p subshell. Thus, the valence-shell configuration for group 5A is represented as . Item 23 Part A For chlorine, identify the group number. ANSWER: 7A Correct Part B Give the number of electrons in each occupied shell. ANSWER: One electron is in shell 1, eight electrons are in shell 2, and eight electrons are in shell 3. Two electrons are in shell 1, eight electrons are in shell 2, and seven electrons are in shell 3. Two electrons are in shell 1, seven electrons are in shell 2, and seven electrons are in shell 3. Two electrons are in shell 1, eight electrons are in shell 2, and eight electrons are in shell 3. Correct Part C Write its valence-shell configuration. ANSWER: 2s22p5 3s23p5 3p5 3s23p4 Correct Item 24 Part A Write the electron-dot symbol for element Draw the electron-dot symbol for element in group 3A. . Use as a typical group 3A element. ANSWER:             X   Correct Item 25 When an electron in a strontium atom drops from the excited state to the ground state, it emits red light, as explained in the Chemistry in Action on p. 66. When an electron in a copper atom drops from the excited state to the ground state, it emits blue light. Part A What are the approximate wavelengths of the red light and the blue light? Check all that apply. ANSWER: The wavelength of red light lies between 400-480 nm. The wavelength of blue light lies between 400-480 nm. The wavelength of red light lies between 700-780 nm. The wavelength of blue light lies between 700-780 nm. Correct Part B Which color is associated with higher energy? ANSWER: Blue light is associated with higher energy. Red light is associated with higher energy. Correct Item 26 Part A How many neutrons are in a sodium atom with an atomic number Z = 11 and a mass number A = 25? Hint 1. What mass number represents Mass number (A) is the total of protons and neutrons in a nucleus. Atomic number (Z) is the total number of protons in a nucleus. ANSWER: 11 14 25 36 Correct Number of neutrons = mass number − atomic number, (or A − Z) = 25 − 11. Item 27 Part A Carbon has two naturally occurring isotopes, 98.89% is C-12 (12 amu exactly) and 1.11% is C-13(13.0034 amu). Calculate the atomic mass for carbon. Hint 1. How to calculate atomic mass from isotopes. Atomic mass = Σ (isotopic abundance) × (isotopic mass) ANSWER: 12.01 amu 12.5 amu 25.0034 amu 12 amu Correct (12 × 0.98.89) + (13.0034 × 0.0111) Item 28 Part A Which one of the following pairs of elements will have similar chemical properties? Hint 1. How to use the periodic table Elements in the same group of the periodic table have similar chemical properties. ANSWER: lithium (Li) and rubidium (Rb) aluminum (Al) and silver (Ag) phosphorus (P) and sulfur (S) silicon (Si) and arsenic (As) Correct Li and Rb are both alkali metals (group 1A). Item 29 Part A Theoretically, what is the maximum number of electrons that can occupy the fifth shell? Hint 1. How to predict the maximum number of electrons in a shell Theoretically, the fifth shell can have 5 subshells containing 1, 3, 5, 7, and 9 orbitals, respectively. ANSWER: 25 50 10 32 Correct 5 subshells, 1 + 3 + 5 + 7 + 9 = 25 orbitals, and therefore, 50 electrons. Item 30 Part A How many dots are in the electron-dot symbol of the main group element Se? Hint 1. How to determine the number of dots in an electron-dot symbol The number of dots in the electron-dot symbol of a main group element is equal to its number of valence electrons and its group number. ANSWER: 4 9 8 6 Correct Selenium is a group 6A element with 6 valence electrons. Score Summary: Your score on this assignment is 96.1%. You received 28.82 out of a possible total of 30 points.