Answer:
d. The correct answer for your questions is Sr<Ca<Be
The enthalpy of vaporization of H2O is higher than the enthalpy of fusion of H2O, therefore vaporizing the same mass of H2O would require more heat/energy than melting the same mass of H2O.
Because more than one substance was released (following a color change signifying a chemical reaction), the sample was indeed, a compound.
<span>The vaporization of br2 from liquid to gas state requires 7.4 k/cal /mol.</span>
Don't know sorry the answer.