16. representative elements are those found in the * a. s and p blocks b. d block c. s and d blocks d. d and f blocks 17. within the representative elements, atomic size generally * a. remains constant within a period b. increases as you move left to right across an energy level c. increases as you move down a group d. cannot be predicted 18. ions are charged particles formed from atoms. which of these would be true? * a. cations form when an atom gains electrons. b. cations form when an atom loses electrons. c. anions form when an atom gains protons. d. anions form when an atom loses protons.

The two naturally occurring isotopes of chlorine are 35cl (34.969 amu, 75.77%) and 37cl (36.966 amu, 24.23%). the two naturally occurring isotopes of bromine are 79br (78.918 rm amu, 50.69%) and 81br (80.916 amu, 49.31%). chlorine and bromine combine to form bromine monochloride, brcl. 1. how many peaks will be present in a mass spectrum for brcl? the four combinations of molecule possible given these four isotopes are: 81br37cl, 81br35cl, 79br37cl, and 79br35cl. 2. what are the masses of the four different brcl molecules? express the masses using six significant figures, in decreasing numeric order (highest to lowest), separated by commas.