A low-pressure mercury-vapor lamp has a characteristic emission line at 253 nm. Knowing that in one second this lamp is putting out 11.8 Joules of light energy, how many mercury atoms emit a photon during this one second of operation?1. 5.25 x 1020 atoms 2. 7.11 x 1024 atoms 3. 1.50 x 1019 atoms 4. 1.08 x 1017 atoms 5. 7.86 x 10â19 atoms 6. 4.73 x 105 atoms

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.

c. is the answer

by love gaming