Answer:
Energy in an ecosystem comes from the Sun.
Explanation:
It is a major source of energy for organisms, plants and the whole ecosystem basically.
Answer:
Calcium is more reactive.
Explanation:
It is higher in the reactivity series, and contains more energy levels.
Answer:
The rock cycle and plate tectonics cause Earth's rocks to break down over time and they are recycled through natural processes.
Explanation:
Rock cycle(Attachment-1)