Which of the following explains the conservation of mass during cellular respiration?

the total number of atoms when carbon dioxide and oxygen react stays the same when glucose and water are produced.
the total number of atoms when water and oxygen react stays the same when glucose and water are produced.
the total number of atoms when carbon dioxide and water react stays the same when glucose and oxygen are produced.
the total number of atoms when glucose and oxygen react stays the same when carbon dioxide and water are produced.

The total number of atoms when glucose and oxygen react stays the same when carbon dioxide and water are produced.

Explanation:

There are two types of respiration:

1.Aerobic respiration  

2.Anaerobic respiration

Aerobic respiration

It is the breakdown of glucose molecule in the presence of oxygen to yield large amount of energy. Water and carbon dioxide are also produced as a byproduct.

Anaerobic Respiration

It is the breakdown of glucose molecule in the absence of oxygen and produce small amount of energy. Alcohol or lactic acid and carbon dioxide are also produced as byproducts.  

This process use respiratory electron transport chain as electron acceptor instead of oxygen. It is mostly occur in prokaryotes. Its main advantage is that it produce energy (ATP) very quickly as compared to aerobic respiration.  

Chemical equation of cellular respiration:

C₆H₁₂O₆ + 6O₂  →  6CO₂ + 6H₂O+ ATP

In cellular respiration glucose react with oxygen and produce carbon dioxide and water and total number of atoms remain same.

The number of oxygen, carbon and hydrogen atoms on reactant side are eighteen, six and twelve respectively.

We can see the same number of atoms of each elements are also present on product side. So. mass is perfectly conserved.  

answer; /// i do believe that the correct answer is (a) boiling

substituting a hydrogen atom with a halogen in a hydrocarbon:

- the single bond remains single. a is wrong.

- the bond with hydrogen is as strong as with a halogen. c is wrong

- a hydrocarbon is saturated if there is no double bond. we do not know that so d is wrong.

- carbon will always have four valence electrons. e is wrong.

by elimination, the correct answer is b. the boiling point of the new compound increases.