Consider the following electron configurations to answer the question: (i) 1s2 2s2 2p6 3s1 (ii) 1s2 2s2 2p6 3s2 (iii) 1s2 2s2 2p6 3s2 3p1 (iv) 1s2 2s2 2p6 3s2 3p4 (v) 1s2 2s2 2p6 3s2 3p5 The electron configuration that belongs to the atom with the lowest second ionization energy is

12. complete each of the following word equations for synthesis reactions. a. sodium + oxygen -> b. magnesium + fluorine -> 13. complete and balance the equations for the decomposition reactions. a. hgo -> [with the triangle heat symbol above the arrow] b. h2o(l) -> [with "electricity" written above the arrow]

Select each correct answer. more than one answer may be correct. which of the following is a characteristic of unicellular organisms? they can possess tissues and organs. all of their functions are performed by a single cell. they are usually microscopic. each of their cells is specialized to perform a specific function.

Which of the following ocean acidification? are the most likely side effects of a ph less than 7.0 in the ocean b. more metal salts altering the ocean chemistry c. dissolution of the shells of marine organisms d. both a & b e. all of the above.