The diagram below shows the heating of an unknown substance (it is not water). Its melting point is? The diagram below shows the heating of an unknown substance. (It is NOT water). Its melting point is: a. between 35⁰C and 70⁰C

b. 70⁰C

c. between 70⁰C and 140⁰C

d. 140⁰C

the answer is B

Melting point, temperature at which the solid and liquid forms of a pure substance can exist in equilibrium. As heat is applied to a solid, its temperature will increase until the melting point is reached. More heat then will convert the solid into a liquid with no temperature change.

when it gains or loses electrons