# Answer hint 3 determine which group the element each

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ANSWER: Hint 3. Determine which group the element each electron configuration specifies should fall under 18 4 34 16 Typesetting math: 92%
Hint 3. Determine which group the element each electron configuration specifies should fall under Groups are the columns of the periodic table. They are numbered 1­18 starting with the s orbitals, moving through the transition metals, and ending with the p orbitals. For example, given the electron configuration \rm 1s^22s^2 , the last orbital filled is the 2 s orbital and it has two electrons. Therefore, given that there are only two electrons in the valence shell, the element must be in group 2 of the periodic table. On the other hand, the electron configuration \rm 1s^22s^22p^1 would correspond to an element in group 13. The d block, groups 3­12, comes between the s and p blocks. Sort each electron configuration into the group (column) on the periodic table that contains the element it represents by using the last orbital filled with electrons. Drag the appropriate items to their appropriate bins.
Correct There are two ways to identify an element being represented by an electron configuration. One is to locate the last occupied sublevel on the periodic table and count down the period the correct number of electrons. The other is to calculate the atomic number by adding up the electrons represented by the exponents (and the atomic number of the noble gas being referenced for abbreviated electron configurations). Element Electron Configuration Silicon ( \rm Si ) \rm 1s^22s^22p^63s^23p^2 Nitrogen ( \rm N ) \rm [He]2s^22p^3 Tantalum ( \rm Ta ) \rm 1s^22s^22p^63s^23p^64s^23d^{10}4p^65s^24d^{10}5p^66s^24f^{14}5d^3 Selenium ( \rm Se ) \rm [Ar]4s^23d^{10}4p^4 Cadmium ( \rm Cd ) \rm [Kr]5s^24d^{10} Magnesium ( \rm Mg ) \rm 1s^22s^22p^63s^2 Part C Write the complete electron configuration for krypton using the periodic table. Express your answer in complete form, in order of increasing orbital. For example, \rm 1s^22s^2 would be entered as 1s^22s^2 . Hint 1. How to approach the problem The following is a guide to writing electron configurations using sublevel blocks: 1. Locate the element on the periodic table. 2. Write the filled sublevels in order, going across each period. 3. Complete the configuration by counting the electrons in the last occupied sublevel block. Hint 2. Determine the order in which the sublevels are filled Rank the following sublevels in the order that they are filled from first to last. Rank the sublevels from first to last in terms of the order they are filled. ANSWER:
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