Answer: Because new substances are formed.
Explanation: A chemical property is any of a material's properties that becomes evident during, or after, a chemical reaction; that is, any quality that can be established only by changing a substance's chemical identity. Once a chemical change occurs it cannot be undone due to the change in chemical identity. The creation of a new substance is not reversible.
Fats , oils , waxes and sterols are collectively known as lipidsand the true fats contain only carbon , hydrogen and oxygen
I think this is what you mean:
H H H H
H-C-C-C-C-H
H H H H
OR
<span>CH3CH2CH2CH3
</span>
If not, clarify and I will be happy to help.