Since 1891 lighting lamps have been manufactured in the Netherlands. The improvement today in comparison to the first lamp is enormous , especially with the intorduction of the gas discharge lamps. The life- time has increased by orders of magnitude . the colour is also an important aspect. Rare earth metal compunds like `CeBr_(3)` are now included to reach a colour temperature of 6000K in the lamp the compounds are ionic solids at room temperature , and upon heating they sublime partially to give a vapour of neutral metal halide molecules . To achieve a high vapour pressure, the sublimation enthalpy should be as low as possible. Conclusion in relation to the previous answers. was adding CsBr a good idea ? Mark the correct answer. `implies` Adding CsBr is counterproductive. `implies` Adding CsBr has no influence `implies` Adding CsBr is advantageous `implies` From these data no clear answer can be given.