The so-called nitrogen rule states that if a compound has an odd number of nitrogenatoms, the value of m/z for its molecular ion will be an odd number. Why?
Chapter 1 Key Terms and Definitions Building Blocks: – Atoms and Molecules Definition of Chemistry: –Science that seeks to understand the properties of matter by studying the particles that compose it. Mixture: – No fixed composition – Homogeneous Mixture Solution; Same throughout –Heterogeneous Mixture Varies in composition or properties. Substance: – Fixed composition – Elements or Compound History and Starting Point Law of Conservation of Mass (Lavoisier) • The total mass remains constant during a chemical reaction. Law of Definite Proportions (Proust) • All samples of a compound have the same composition (proportions, by mass, of the elements present). Atomic Theory of Matter (Dalton) Law of Multiple Proportions • The masses of one element that combine with a fixed mass of the second element are in the ratio of small whole numbers. Experiment: N reacts with O to form two compounds. If 5.0 g of N is used, then one compound takes 5.7 g of O and the other 11.4 g. Ratio is 2:1. • All matter is composed of atoms: extremely small, indivisible particles. • All atoms of a given element are alike in mass and other properties, but differ from atoms of other elements. • Compounds a