LASERS The successful separation of hydrogen isotopes by selective laser-induced chemical reaction has further established the laser as a powerful tool in physicochemical applications. This method, following the development of a continuous-wave hydrogen-fluorine laser, demonstrates the integration of physics and chemistry in continuous-wave gas lasers. Isotope separation is achieved by irradiating mixtures of ordinary and deuterated methanol and bromine with 0.44 eV photons at 100 watts. The reaction is specific to ordinary methanol, leading to an enrichment of deuterated compounds from 50% to over 95%. This method has potential for observing specific vibrational modes of reactive molecules, opening new avenues in chemical kinetics. FIBRES A study on the effect of solutes on the indentation hardness of β-boron found that copper, scandium, and manganese solutes increased hardness by about 20% compared to pure β-boron. This suggests that alloyed boron could be used to produce stronger fibers or whiskers. Recent findings also indicate that boron-fiber alloys may be particularly strong. NIAGARA The method described is unlikely to be effective for heavier isotopes, but could be competitive with other methods if chemical ingenuity and recycling are applied. REGRESSING FALLS The Niagara River is unusually constant due to its unique geographical features. STRUCTURAL INORGANIC CHEMISTRY The selectivity in the laser experiment depends on matching the laser frequency to the vibration of the -OH bond, without involving kinetic isotope effects. The process is not easily classified by current photochemical terms, indicating its originality. Organotransition metal chemistry has grown significantly, with important implications for catalysis. Structural studies and symmetry arguments are key in understanding bonding and geometries. The Jahn-Teller effect is used to explain distortions in transition metal complexes. Symmetry considerations help predict favored nuclear rearrangements in organometallic molecules. While this approach has limitations, it may be as useful as Walsh's rules for simpler systems.LASERS The successful separation of hydrogen isotopes by selective laser-induced chemical reaction has further established the laser as a powerful tool in physicochemical applications. This method, following the development of a continuous-wave hydrogen-fluorine laser, demonstrates the integration of physics and chemistry in continuous-wave gas lasers. Isotope separation is achieved by irradiating mixtures of ordinary and deuterated methanol and bromine with 0.44 eV photons at 100 watts. The reaction is specific to ordinary methanol, leading to an enrichment of deuterated compounds from 50% to over 95%. This method has potential for observing specific vibrational modes of reactive molecules, opening new avenues in chemical kinetics. FIBRES A study on the effect of solutes on the indentation hardness of β-boron found that copper, scandium, and manganese solutes increased hardness by about 20% compared to pure β-boron. This suggests that alloyed boron could be used to produce stronger fibers or whiskers. Recent findings also indicate that boron-fiber alloys may be particularly strong. NIAGARA The method described is unlikely to be effective for heavier isotopes, but could be competitive with other methods if chemical ingenuity and recycling are applied. REGRESSING FALLS The Niagara River is unusually constant due to its unique geographical features. STRUCTURAL INORGANIC CHEMISTRY The selectivity in the laser experiment depends on matching the laser frequency to the vibration of the -OH bond, without involving kinetic isotope effects. The process is not easily classified by current photochemical terms, indicating its originality. Organotransition metal chemistry has grown significantly, with important implications for catalysis. Structural studies and symmetry arguments are key in understanding bonding and geometries. The Jahn-Teller effect is used to explain distortions in transition metal complexes. Symmetry considerations help predict favored nuclear rearrangements in organometallic molecules. While this approach has limitations, it may be as useful as Walsh's rules for simpler systems.