Question

answers given but please show work on how you get to that answer.

16. Which one of the following statements about valence electron c Tollowing statements about valence electron configurations is incorrect? A) A single neutral phosphorus atom, P, has 5 valence electrons. B) A single neutral carbon atom, C, has 2 unpaired valence electrons. (C) A single neutral sulfur atom, S, has 2 valence electrons. D) A single neutral nitrogen atom, N, has 3 unpaired valence electrons. E) A calcium cation, Ca2+, has 0 valence electrons. 11. Which one of the following statements about the elements sulfur and chlorine is incorrect? A) An S2. anion is larger than a Cl' anion. B) An Satom is larger than a Clatom. C) An S2. anion is isoelectronic to a Cl' anion. D) The first ionization energy of an Satom is lower than the first ionization energy of a Cl atom. The electron affinity of an Satom is higher than the electron affinity of a Cl atom. 18. What percent of a radioactive sample remains after 4 half lives? A) 6.2% B) 3.1% C) 20% D) 50% E) 500% 19. Calculate the AHrxn for the following reaction using the given bond energies: CH4(g) + 2H2O(g) -> 4H2(g) + CO2(g) Bond Bond Energy (kJ/mol) H-H 436 O-H 464 H-C 414 C=0 799 A) -2110 kJ B) -375 kJ 9 -170 kJ DY +170 kJ

Answer 1

(16) S eleefron se configuration - 6 valence electrons 33 t 3p6 wwn te a Noble gas configu sation (stable) S → Walates Worth D Newly acelee electron andlego es repulsion with eppsting electrons. a on getting one electrone attach stable noble gas configurate on I fell filled) (18) percentage of radioaefrue denuple verwarm = liten gn) 100 ofis 1 [ne number of half lives' - he (54 M100 = (08625 100) x. = 625.). Polotone = En stolprentuner - nolfreactant , Lolion = 4 x D49X2 + 1 X 248202 -014Chyca) + 2 X 864 1720 (9) = 4* (2 x 84) +20 (2Bezo) – {4%BE-H + 2x (2x Bo-H) = 4*(8x436) + 20 (2x Fara) — 248414 + 20 (2M 464)? =- 70 kJ le is correct)