The brain is part of the central nervous system.
Nerves and sensors are part of the peripheral nervous system. Only the brain and spinal cord make the central nervous system.
Answer: 10
Explanation:
The detailed solution is contained in the image attached. The molar mass of hydrated and anhydrous salts are obtained and the number of moles of hydrated and hydrated salts are equated. The masses of hydrated and anhydrous salts are gives in the question and are simply substituted accordingly. This can now be used to obtain the number of molecules of water of crystallization as required in the question.
The third option because the elements mentioned in that selection are in the same group, they must have similar properties.
C) and d) are physical changes while b) is chemical