I think the answer is that is lights up?
Answer:
Biosphere
Explanation:
The biosphere covers all living organisms on Earth. There is an estimated 20 million to 100 millions different species in the world organized into the 100 phyla that make up the five kingdoms of life forms. These organisms can be found in almost all parts of the geosphere.
Given :
Molarity of acetic acid solution, M = 0.10 M.
pKa of acetic acid, pKa = 4.75 .
To Find :
Percentage dissociation of 0.10 M solution of acetic acid.
Solution :
We know, 
Taking antilog both side, we get :

Since, acetic acid has 1 hydrogen atom to loose , so it is a monoprotic acid.
Now, percentage dissociation of monoprotic acid is given by :

Hence, this is the required solution.