Light is a form of energy that travels in the wave it does not need any material to Carry its energy humans can see the range of light in the visible light spectrum based on this description How is sound different than light?

some sources quote the lethal dose, for an average 170lbs opiate-naive individual is between 75 and 375 mg

b. accuracy of the data matters alot more than its number of digits, organization or amount of detail. quantitative observation is more accepted than the qualitative observation.

water at room temperature is flowing through a pipe with pressure taps located 10 ft apart along one section of the pipe, which are connected to a mercury (s=13.6) manometer.

the ratio of the conjugate base to the acid required to attain the desired ph.