The melting points of the compounds from the choices are listed below:
a. C25H52 -> +47 to +56 degrees celsius
b. Hg -> -38.83 degrees celsius
c. CaCl2 -> +772 degrees celsius
d. CuO -> +1326 degrees celsius
It is evident from the listed melting points above that mercury (Hg) has the lowest melting point. This is why mercury is liquid at room temperature.
What is homogeneous?
A homogeneous mixture is a solid, liquid, or gaseous mixture that has the same proportions of its components throughout any given sample.
