Why is work and heat energy always viewed from the perspective of the system?
The problem is in the word &quot;always&quot;. The statement &quot;Work and heat energy are always viewed from the perspective of the system?&quot; is wrong. Please inform your teacher that is true in the chemist's world only- and chemists did not invent thermodynamics.
Chemists have adopted a different convention than physicists. All we have to do is to be aware of the context.
Recall the First Law of Thermodynamics, which has 2 different equivalent statements.
In some books it is
$$∆U=q-w$$
and in some it is
$$∆U=q+w$$
Why, because the word &quot;always&quot; is not correct.