I don’t know what you mean by classification exactly but it is a redox equation. The reactant side of carbon is losing hydrogen to form carbon dioxide. And oxygen is gaining hydrogen which gives you the water. Redox reactions are also known as combustion reactions.
Answer:
Ionic bonding is the complete transfer of valence electron(s) between atoms. It is a type of chemical bond that generates two oppositely charged ions. In ionic bonds, the metal loses electrons to become a positively charged cation, whereas the nonmetal accepts those electrons to become a negatively charged anion.
The solution changed color because the substances are not neutral.
<h3>
pH</h3>
Chemical substances have different concentrations of the hydrogen cation, called PH.
The higher the pH, the more basic the substance, and the lower the more acidic.
Bromothymol blue is a pH indicator that changes its color according to the pH of the substance, yellow for acid, blue for basic and green for neutral.
In the case of the reactions in question, we have the release of CO2 (acid) in combustion and in cellular respiration, changing the color of bromothymol blue to yellow.
Learn more about pH in: brainly.com/question/491373
Answer : The energy of the photon emitted is, -12.1 eV
Explanation :
First we have to calculate the 
orbit of hydrogen atom.
Formula used :
where,
= energy of 
orbit
n = number of orbit
Z = atomic number of hydrogen atom = 1
Energy of n = 1 in an hydrogen atom:
Energy of n = 2 in an hydrogen atom:
Energy change transition from n = 1 to n = 3 occurs.
Let energy change be E.
The negative sign indicates that energy of the photon emitted.
Thus, the energy of the photon emitted is, -12.1 eV
