Which refers to a measure of how acidic or basic a solution is? a]pH b]solubility c]reactiveness d]hardness

Option(a) i.e" pH" is the correct answer to the given question .

Explanation:

The main objective of pH value is to determining whether the solution is the acidic or the basic solution.The pH is determining the solution whether it is basic or acidic with the help of there pH value .The range of the pH value is from 0 to 14 with the following parameter it determines whether the solution is basic ,acidic or the neutral solution  .

All the other option are not determining that whether the solution is acidic or the basic solution that's why these are incorrect option .

speed of light in vacuum is 300,000 km/s

speed of light in other mediums is given by the expression v = c/n, where c is the speed of light in vacuum and n is the refractive index of medium.

for the first medium v = 200,000 km/s

  so, refractive index of medium = 300000/200000 = 1.5

    1.5 refractive index is usually for glass. so first medium is glass.

for the second medium v = 250,00 km/s

so, refractive index of medium = 300000/250000 = 1.2

    1.2 refractive index is usually for water. so second medium is water.

for the third medium v = 0 km/s

so, refractive index of medium = 300000/0 = ∞

    ∞ refractive index is usually for opaque mediums. so third medium is opaque medium.