How would a system in which both matter and energy are exchanged freely between the system and the surroundings be classified?

 Open System

Explanation:   System can be classified into 3 types-

a) Open System - In this kind of system, matter and energy both are exchanged freely with the surroundings.

Example - A tea in a container with the open lid.

b) Closed System - In this kind of system, matter cannot be exchanged but energy can be exchange with the surroundings.

Example - A tea in the container with closed lid.

c) Isolated System - In this, neither energy or matter can be exchanged with the surroundings.

Example - A tea in an insulated thermal flask.

Thus the system in which matter and energy are exhanged freely between the syste and the surroundings is classiifed as Open System.

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.

it would be b. 6co2 + 6h2o --> c6h12o6 + 6o2