18. a substance has a definite volume
but takes the shape of its container.
a student heats the substance.
the substance expands, filling the
container. which change of state did
the student most likely observe?
^ a change from a liquid to a gas
@ a change from a solid to a liquid
© a change from a liquid to a solid
a change from a gas to a liquid

change from a gas to aliquid

Explanation:

because gases expand when heated

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

if it's not useful, feel free to report for mistake in answer.