Bones are made up of Calcium Phosphate given by the chemical formula, 
. When bones are kept in Hydrochloric acid, given by the chemical formula, HCl, they become soft because the calcium compound present in the bones changes its form. The following double displacement reaction takes place when the bones are kept in HCl,
---> 
Calcium chloride is water soluble, and gets washed away. This makes the bone thin and soft.
It is potential energy is converted into apt energy for use in living things.
Answer:
C AND E?
Explanation:
If it's right let me know. If not, then you can tell me the answer so I can change it for everyone to get the answer
A Respiration by animals CO2 is being added.
B trees burning same
C tree leaves removed
D oil added
