Chlorine Mass Spectrum Isotopic Analysis Steps: - Identify key peaks: Cl+ at m/z 35 (75% abundance) and 37 (25%); Cl2+ at m/z 70 (35Cl-35Cl), 72 (35Cl-37Cl), 74 (37Cl-37Cl), forming five peaks total. - Evaluate statement 1: Use abundances and m/z of all five peaks to derive isotope ratio, then calculate relative atomic mass via weighted average: $A_r = \frac{(35 \times I_{35} + 37 \times I_{37})}{I_{total}}$. - Evaluate statement 2: Peaks W, X, Y likely atomic or partial molecular ions; their abundances and m/z allow pattern recognition to assign mass of Z (e.g., higher isotope combination). - Evaluate statement 3: Peaks X and Y (subset of Cl2+ ions) omit full isotopic distribution, preventing accurate relative molecular mass calculation for Cl2. Why A is correct: - Statements 1 and 2 use complete or patterned data for valid mass derivations, per mass spectrometry principles for isotopes. Why the others are wrong: - B omits correct statement 2, which enables Z mass calculation from spectral patterns. - C omits correct statement 1, essential for atomic mass from full peak set. - D …