1. natural environment; nutrient setting for microorganism.   medium   insomnia   iota   parasite   Hint Half-n-half Clue   2. residue from smelting operation.   slag   vise   trajectory   parasite   Half-n-half Clue   3. layer of earth's crust or society.   placebo   mammal   panacea   stratum   Half-n-half Clue   4. amount produced or income earned.   panacea   yield   parasite   projectile   Half-n-half Clue   5. smallest particle of a substance with all its properties.   patina   molecule   innovation   velocity   Half-n-half Clue   6. unit for measuring light energy.   insomnia   lumen   innovation   log   Half-n-half Clue   7. substance that causes solid matter in solution to deposit.   pestle   kaleidoscope   precipitant   log   Half-n-half Clue