Question

what characterizes the earth as an open system, especially in terms of energy?
the earth absorbs energy from the sun as heat and does not release it.
the earth receives energy from the sun as sunlight and releases energy as heat.
the earth emits energy as sunlight into space and does not absorb any.

Explanation:

An open system exchanges energy and matter. Earth gets solar energy (sunlight) and releases heat (thermal energy) back to space, fitting the open - system definition. Option A is wrong as Earth does release heat. Option C is incorrect because Earth doesn't emit energy as sunlight; it's the Sun that emits sunlight.

Answer:

B. The Earth receives energy from the Sun as sunlight and releases energy as heat.