Question

which of the following best describes energy flow on earth?
(1 point)

earth is a closed system; only energy is exchanged with the surroundings.
earth is an open system; only energy is exchanged with the surroundings.
earth is a closed system; no matter or energy is exchanged with the surroundings.
earth is an open system; no matter or energy is exchanged with the surroundings.

Explanation:

A closed system is one where matter does not enter or leave, but energy can be exchanged. Earth receives energy from the Sun (solar energy) and radiates energy back into space, while the amount of matter (like rocks, water, air in the overall planetary sense) that enters or leaves Earth is negligible. An open system exchanges both matter and energy, which is not the case for Earth in terms of matter exchange (on a large, planetary scale). The other options either misclassify Earth as open (when matter exchange is minimal) or say no energy/matter is exchanged (which is wrong as energy is exchanged). So the correct option is the one stating Earth is a closed system with only energy exchanged.

Answer:

A. Earth is a closed system; only energy is exchanged with the surroundings.