True or false all substances have the same melting point​

false

false this is because all subtances are mixture of different element. elements doesnt have the aame boiling point.

specific gravity is the density of a substance divided by the density of water. since (at standard temperature and pressure) water has a density of 1 gram/cm3, and since all of the units cancel, specific gravity is usually very close to the same value as density

so "c" is the answer

plz give brainliest

c. heat could easily travel through the molecules in the air and escape/enter the flask. removing the air slows down the heat transfer.