about system and surroundings

[Eugene Chung 3F]

How do you know which is the system and which is the surrounding?
For example, for 4A 1, for mercury in a thermometer or gasoline burning in an automobile engine, could someone tell me what is the system and surrounding in these two cases?

[kristi le 2F]

The system is the region of interest and the surroundings is everything else. So, in these cases, the thermometer and the engine would be the systems. Everything else would be the surroundings.

[CosetteBackus_4F]

A system is the object of interest whereas the surroundings are everything else. In this case the thermometer is an open system and the engine is a closed system.

[Joanne Lee 1J]

The system is the object that is of interest and the surrounding is anything else that might be involved in the experiment.

[Kimberly Koo 2I]

The system is what we're interested in, and the surroundings are everything else around the system

[805097738]

so the surrounding is the universe?

[Amir Bayat]

so the surrounding is the universe?

Essentially yes, the surrounding can be the universe. However the system is what we are specifically observing in the universe.

[Caroline Beecher 2H]

The system is the part of the universe we are studying (ex: reaction, gas, closed, open, or isolated systems). The surroundings include everything else (universe) but usually we are just looking at particular surroundings.

[haileyramsey-1c]

so the surrounding is the universe?

The universe is the surrounding plus the system. The system is what we are observing or interested in where as the surrounding is the components around it. In a calorimeter the water the substance is dissolved in is they surroundings and the substance is the system.