Explanation:
Heat necessary to raise the temperature of a substance by unit mass of a given substance by a given amount is known as specific heat.
It is known that relation between heat energy, specific heat, and mass is as follows.
q = [tex]m \times C \times \Delta T[/tex]
As the specific heat of water is 4.18 [tex]J/g^{o}C[/tex] and the specific heat of gold is 0.129 [tex]J/g^{o}C[/tex]. Since, the specific heat of water is greater than the specific heat of gold.
Therefore, we can conclude that water is more efficient to warm your bed on a cold night with a hot water bottle that contains 1 kg of water at 50 degrees C.