Water
Enzymes
False.
It depends on the nature of the decomposition. if you are talking about biodegradeability in a substance, then no, its decomposition is mainly due to bacteria that will break down the various particles in the substance ("eat" them). There are, however certain chemical reactions which take place within the bacteria as the substance is being broken down, (much like those that happen in the human body) and the possibility of there being other products in the vicinity which may react to the substance (and degrade it) is always present. It could be said that decomposition is therefore a chemical reaction (or rather a series thereof), but with biodegradeability in mind it is not generally thought of as such.
By mass Oxygen
Sulfur bonds with all sorts of other chemicals, forming various compounds. In the body, chemical reactions take place where those compounds get broken down, thus releasing sulfur as a free element.
The most abundant chemical substance in the human body is water. There are a lot of H2O molecules throughout the human body.
This substance is water, H2O.
Dihydrogen monoxide
Mind is the second most abundant substance in the human body
According to Marieb, 8th edition, "Electrolytes are the most abundant solutes in body fluids and determine most of their chemical and physical reactions"
Water (H2O)
Collagen is the most abundant protein found in your body.
The human body is made up mostly of water.
h2o
substance created by the body to carry out chemical digestion substance created by the body to carry out chemical digestion
H2O or water!
Water would be the most abundant substance but if you're asking about elements then oxygen would make up the greatest percentage of body mass.