5. Which element has the greatest second ionization energy? (A) Mg (B) Ca (C) K (D) Al (E) Na

10. Consider the following Lewis structure. (Lone pairs are not drawn in.) Which statement about the molecule is false? (A) This molecule contains 28 valence electrons. (B) C-2 is sp² hybridized with bond angles of 120°. (C) Oxygen is sp³ hybridized. (D) There are 10 σ (sigma) and 2 π (pi) bonds. (E) There are some H–C–H bond angles of about 109° in the molecule.