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.
Answer:
B
Explanation:
In a command Economy, 1 is right. 3 and 4 are plain Rubbish.
D. 99% of all living things that have ever existed are now extinct
Answer: c. The myosin would not be able to let go of the actin
Explanation:
Muscles consists of two proteins called actin and myosin and responsible for muscle contraction.
Myosin is ATP dependant and when ATP binds to it, it is able to release the actin.
This will allow the actin and myosin to seperate from each other thus leading to muscle contraction
The main form is carbon dioxide and methane
