Question

Solveeeeèeeeee this?

Answer 1

heating a metal rod charges its atoms which causes it to move & reduce attraction between each other.Hence,surface expansion & volume expansion takes place

Answer 2

heating a iron rod at it melting point break the intermoleculer force of cohesion or attarction and change its state which liquid.
heating an iron also depends on the container in which it is melting and the quantity also depends.