Answer:
The Earth is essentially a closed system; it obtains lots of energy from the Sun but the exchange of matter with the outside is almost zero. Isolated systems can exchange neither energy nor matter with an outside system.
The Precambrian was originally defined as the era that predated the emergence of life in the Cambrian Period. It is now known, however, that life on Earth began by the early Archean and that fossilized organisms became more and more abundant throughout Precambrian time.
Well, there's producers and consumers. There is also one provider that is the main source of energy for all living things which is the sun. The sun provides sunlight for the producers to make their own food through photosynthesis then consumers come and eat the producers(plants) and that gives them energy. And then predators come and eat that animal and that provides their energy.
The characteristic of life that relies on the sun is the need for energy. Every living thing needs energy in order to survive, and almost every form of life on Earth depends on the sun for this energy. The sun's energy is captured and harnessed by the process of photosynthesis.
The answer is B . two atoms exchange electrons and become ions