Answer:
because there more acid in diet cola
Don’t worry about it, let me do your homework!
Born February 27, 1869, Alice Hamilton was an American physician, research scientist, and author who is best known as a leading expert in the field of occupational health and a pioneer in the field of industrial toxicology. She was also the first woman appointed to the faculty of Harvard University.
Answer to this is Radioactive isotopes.
Isotopes are the species of the same element having different atomic masses that means the number of protons remains the same but number of neutrons do differ. For example
and
are the two isotopes of Hydrogen (
).
Radioactive isotopes are the isotopes which release some kind of energy in the form of alpha particles, beta particles or gamma radiation. Examples of each of the decay processes are :
Alpha Decay: In this decay one alpha particle having atomic mass 4 and atomic number 2 or we can say a He molecule will come out. 
Beta Decay: In this decay a
particle is emitted increasing the atomic number of the reactant by 1 unit.

Gamma Radiation: In this type of reaction only radiation is emitted out which does not change the original molecule.

During cellular respiration, the carbon and hydrogen atoms change partners and bond with oxygen atoms instead. The carbon-hydrogen bonds are replaced by carbon-oxygen and hydrogen-oxygen bonds. As the electrons of these bonds "fall" toward oxygen, energy is released.
Chemical would be the correct answer